Marine asset security and tracking (MAST) system

ABSTRACT

Methods and apparatus are described for marine asset security and tracking (MAST). A method includes transmitting identification data, location data and environmental state sensor data from a radio frequency tag. An apparatus includes a radio frequency tag that transmits identification data, location data and environmental state sensor data. Another method includes transmitting identification data and location data from a radio frequency tag using hybrid spread-spectrum modulation. Another apparatus includes a radio frequency tag that transmits both identification data and location data using hybrid spread-spectrum modulation.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY-SPONSOREDRESEARCH OR DEVELOPMENT

This invention was made with United States Government support underprime contract No. DE-AC05-00OR22725 to UT-Battelle, L.L.C. awarded bythe Department of Energy. The Government has certain rights in thisinvention.

BACKGROUND OF THE INVENTION

1. Field of the Invention

An embodiment of the invention relates generally to the field ofsecurity and tracking. More particularly, an embodiment of the inventionrelates to marine asset security and tracking (MAST).

2. Discussion of the Related Art

The worldwide ocean-going freight transportation infrastructure, knownas the Marine Transportation System (MTS), is under stress from severalfronts including: terrorism, antiquated technology, environmentalrestrictions, just-in-time manufacturing practices, overlappingstate/federal/local jurisdictions, and a lack of basic technologicalinfrastructure. Terrorist attacks may likely focus on economic terrorismto affect change in the modern world. One need only look to the openmovement of containerized cargo to find simple, effective, and efficientmeans of large-scale economic damage (RFID Journal, 2003). Thedestruction, or the stoppage of flow at a few key ports could damage oureconomy and cripple the nation in a matter of weeks (Flynn, 2003).Consequently, there is a need to develop and deploy tracking andmonitoring technologies at the container level to help secure the globalsupply chain and the critical port facilities that service the economicwell-being of our nation and other nations (Gills and McHugh, 2002;Bonner, 2002; Verton, 2002).

A port is an assemblage of many facilities, entities and functionsincluding: federal stakeholders (e.g., U.S. Customs, Coast Guard, DOD,TSA, FBI, etc.), state government stakeholders (e.g., Ports Authority,State Law Enforcement, Emergency Preparedness, etc.), and localstakeholders (e.g., local law enforcement, local fire departments, portsecurity, and commercial terminal operators, labor unions, etc.).Developing additional facilities to network the critical components ofoperations at each port to provide for port security/management andship/cargo security/tracking/management will aid in efficient use andsafety of each port. Ultimately, these local port facilities should belinked to a regional center and/or national center with potential forinternational expansion. Consequently, there is a need to adopttechnologies, such as geographic information systems (GIS), globalsatellite communications, the internet, and wirelessmonitoring/tracking/security infrastructure in managing/securing themodern supply chain preferably with an open systems architecture toallow multiple public and private entities to participate.

Shipping via the Marine Transportation System (MTS) totaled $480 billionin cargo and contributed $750 billion to the U.S. gross domestic productin calendar year 1999, and the current volume of domestic maritimeshipping is expected to double (USDOT, 1999) over the next 20 years.International maritime shipping is expected to triple over the same timeperiod (Prince, 2001). Many port facilities are under economic stressfrom the above-noted several fronts, including antiquated technology,environmental restrictions, just-in-time manufacturing practices,overlapping federal/state/local jurisdictions, and the lack of basictechnological infrastructure to orchestrate a secure and efficientcontainer management system. In addition, land competition andenvironmental regulations will restrict the geographic expansion of mostcurrent port facilities. The information systems tasked with managingcontainers are still largely dependent on manual data entry.Consequently, there is a need for automated technology solutions toincrease efficiency and security in port facilities (Gills and McHugh,2002; Verton, 2002; Gillis, 2002).

In addition to concerns about MTS economic inefficiencies, the MTScurrently has an unprecedented emphasis on homeland security. In 2001,5.7 million containers entered the U.S. via the MTS (Gills and McHugh,2002). U.S. Customs inspects less than 2% of these containers manually,relying on intelligence to “profile” containers. The Coast Guard andU.S. Customs do not have the manpower or resources to manually searcheach container entering the U.S., and doing so would bring the supplychain to a catastrophic halt (Loy, 2002). Intelligent profiling of cargoand containers is critical to securing the global supply chain andenabling legitimate commerce. Tracking and monitoring would providebetter data from which to build intelligent profiles. Therefore, thereis a need for investment in appropriate tracking and monitoringtechnology as the key to increased security and economic efficiency(Flynn, 2003).

A key concern with containerized cargo transportation is the relativeease with which a thermonuclear device or radioactive material for a“dirty bomb” could be smuggled into the target country in a shippingcontainer. A significant specific problem for Homeland Security is thepotential shipping of radioactive material for a “dirty bomb” into theUnited States in a shipping container. The standard marine shippingcontainer has become the dominant method of importing and exportinggoods worldwide. The number of containers arriving and departing from USports each day is so large that only an extremely small fraction is everinspected. Since only a small fraction of containers can ever beinspected, some method must be employed to “flag” containers forinspection. Locating sensor portals through which each container mustpass at each port facility is considered unrealistic. Such a bottle neckcould cost the US economy billions of dollars each day. Employing aradiation sensor in, on or near the cargo container to look for elevatedlevels of radiation would be one method of flagging containers.

However, there are problems with existing radiation sensors that havebeen proposed for shipping containers. First, existing radiation sensorsmust use power during the dose integration (active sensing) time.Existing active radiation sensors must either utilize very shortintegration times, thus reducing sensitivity, or they will use up theiravailable battery power long before the end of the service life of thecontainer. Replacing batteries requires maintenance personal time,coordination between the maintenance schedule and the physical locationof the container and logistical support. There is a need for radiationsensors with a much longer unattended service life.

Second, existing active radiation sensors do not make the doseintegration data available for secure and uninterrupted monitoring ofthe each container. Reading the dose integration data requires that theindividual sensors be removed and read, or at least individually read,leading to the same problems of costly maintenance personal time,coordination between the data collection schedule and the physicallocation of the container and logistical support. There is a need forradiation sensors that make the dose integration data automatically andremotely available for intelligent profiling and analysis.

Third, existing active radiation sensors are prone to false alarms.Existing active radiation sensors cannot discriminate between differenttypes of radiation leading to false alarms from substances used formedical diagnosis and even from benign cargo such as bananas whichnaturally contain concentrations of ionizing radiation substances (e.g.,potassium). There is a need for more sophisticated and discriminatoryradiation sensors.

Heretofore, the requirements of container-level tracking and monitoringby long-life sensors, making the critical data automatically andremotely available for intelligent profiling and analysis and reducingfalse alarms have not been met. What is needed is a global containersecurity and asset (ship and cargo) tracking system that satisfies(preferably simultaneously all of) these requirements.

SUMMARY OF THE INVENTION

There is a need for the following embodiments of the invention. Ofcourse, the invention is not limited to these embodiments.

According to an embodiment of the invention, a method comprises:transmitting identification data, location data and environmental statesensor data from a radio frequency tag. According to another embodimentof the invention, an apparatus comprises: a radio frequency tag thattransmits identification data, location data and environmental statesensor data.

According to another embodiment of the invention, a method comprisestransmitting identification data and location data from a radiofrequency tag using hybrid spread-spectrum modulation. According toanother embodiment of the invention, an apparatus comprises a radiofrequency tag that transmits both identification data and location datausing hybrid spread-spectrum modulation.

According to another embodiment of the invention, a method comprisesinsitu polling a suite of passive integrating ionizing radiation sensorsincluding reading-out dosimetric data from a first passive integratingionizing radiation sensor and a second passive integrating ionizingradiation sensor, wherein the first passive integrating ionizingradiation sensor and the second passive integrating ionizing radiationsensor remain situated where the dosimetric data was integrated whilereading-out. According to another embodiment of the invention, anapparatus comprises a first passive integrating ionizing radiationsensor; a second passive integrating ionizing radiation sensor coupledto the first passive integrating ionizing radiation sensor; and acommunications circuit coupled to the first passive integrating ionizingradiation sensor and the second passive integrating ionizing radiationsensor, wherein the first passive integrating ionizing radiation sensorand the second passive integrating ionizing radiation sensor read-outdosimetric data to the communications circuit.

According to another embodiment of the invention, a method comprisesarranging a plurality of ionizing radiation sensors in a spatiallydispersed array; determining a relative position of each of theplurality of sensors to define a volume of interest; collecting ionizingradiation data from at least a subset of the plurality of ionizingradiation sensors; and triggering an alarm condition when a dose levelof an ionizing radiation source is calculated to exceed a threshold.According to another embodiment of the invention, an apparatus comprisesa plurality of ionizing radiation sensors arranged in a spatiallydispersed array where a relative position of each of the plurality ofsensors array is determined to define a volume of interest; a datacollection circuit coupled to the plurality of ionizing radiationsensors to collect ionizing radiation data from at least a subset of theplurality of ionizing radiation sensors; and a computer coupled to thedata collection circuit to i) calculate a dose level of an ionizingradiation source and compare the dose level to a threshold and ii)trigger an alarm when the dose level is equal to or greater than thethreshold.

These, and other, embodiments of the invention will be betterappreciated and understood when considered in conjunction with thefollowing description and the accompanying drawings. It should beunderstood, however, that the following description, while indicatingvarious embodiments of the invention and numerous specific detailsthereof, is given by way of illustration and not of limitation. Manysubstitutions, modifications, additions and/or rearrangements may bemade within the scope of an embodiment of the invention withoutdeparting from the spirit thereof, and embodiments of the inventioninclude all such substitutions, modifications, additions and/orrearrangements.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings accompanying and forming part of this specification areincluded to depict certain embodiments of the invention. A clearerconception of embodiments of the invention, and of the componentscombinable with, and operation of systems provided with, embodiments ofthe invention, will become more readily apparent by referring to theexemplary, and therefore nonlimiting, embodiments illustrated in thedrawings. Embodiments of the invention may be better understood byreference to one or more of these drawings in combination with thedescription presented herein. It should be noted that the featuresillustrated in the drawings are not necessarily drawn to scale.

FIG. 1 illustrates a schematic perspective overview of a marine assetsecurity and tracking (MAST) system, representing an embodiment of theinvention.

FIG. 2 illustrates a schematic view of a radio frequency RF data linkoperation for use both onboard ship and in terminal with radio frequencyidentification (RFID) tags able to communicate with both shore-based andship-based receivers simultaneously, representing an embodiment of theinvention.

FIG. 3 illustrates a schematic view of communications between RFID tagsand a network operations center (NOC) via land-side or ship-board siteserver when the tags are utilizing RF for local-area communications(e.g., for ship-board and terminal local area (land-side) operations),representing an embodiment of the invention.

FIG. 4 illustrates a schematic view of a bidirectional communicationsbetween RFID tags and a network operations center (NOC) when utilizingthe cellular or satellite communications during over-the-road or railtransportation, representing an embodiment of the invention.

FIG. 5 illustrates a schematic block diagram of the functionalcomponents comprising an RFID tag, representing an embodiment of theinvention.

FIG. 6 illustrates a schematic perspective view of readers and RFID tagsin the context of a stacked array of containers, representing anembodiment of the invention.

FIG. 7 illustrates a flow diagram of a RFID tag boot-up sequence -including a node discovery sequence mode that can be implemented by acomputer program, representing an embodiment of the invention.

FIG. 8 illustrates a flow diagram of a RFID tag boot-up sequence modethat can be implemented by a computer program, representing anembodiment of the invention.

FIG. 9 illustrates a schematic top plan-view of a group of tightlystacked containers (nominally 40-footers) on the deck of a ship orwithin a terminal yard, with a single RF emitter (depicted as aradiating dot) mounted near the center of the top of it's hostcontainer; the arrows denote RF energy leaking from the ends of thecontainer into adjacent aisles and then reflecting along the aisles; andpotential RF receiving locations are denoted by the dots located at theends of the aisles, representing an embodiment of the invention.

FIG. 10 illustrates a schematic block diagram of an insitu polled suiteof sensors, each sensor having a different filter, representing anembodiment of the invention.

FIG. 11 illustrates a schematic structural diagram of an insitu polledsensor with integrated temperature compensation, representing anembodiment of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiments of the invention and the various features and advantageousdetails thereof are explained more fully with reference to thenonlimiting embodiments that are illustrated in the accompanyingdrawings and detailed in the following description. Descriptions of wellknown starting materials, processing techniques, components andequipment are omitted so as not to unnecessarily obscure the embodimentsof the invention in detail. It should be understood, however, that thedetailed description and the specific examples, while indicatingpreferred embodiments of the invention, are given by way of illustrationonly and not by way of limitation. Various substitutions, modifications,additions and/or rearrangements within the spirit and/or scope of theunderlying inventive concept will become apparent to those skilled inthe art from this disclosure.

The below-referenced U.S. patents, PCT published applicationsdesignating the U.S. and U.S. patent applications disclose embodimentsthat are useful for the purposes for which they are intended. The entirecontents of U.S. Pat. Nos. 6,603,818; 6,606,350; 6,625,229; 6,621,878;6,556,942 are hereby expressly incorporated by reference herein for allpurposes. The entire contents of PCT published application Nos. WO02/27992; WO 02/19550; WO 02/19293; and WO 02/23754 are herebyincorporated by reference for all purposes. The entire contents of U.S.Ser. No. 09/671,636 filed Sep. 27, 2000; Ser. No. 09/653,788 filed Sep.1, 2000; Ser. No. 09/942,308 filed Aug. 29, 2001; Ser. No. 09/660,743filed Sep. 13, 2000; Ser. No. 10/726,446 filed Dec. 3, 2003; Ser. No.10/726,475 filed Dec. 3, 20003; and 10/817,759 filed Dec. 31, 2003 arehereby expressly incorporated by reference herein for all purposes. Theinstant application contains disclosure that is also contained incopending U.S. Ser. No. ______ (Attorney Docket No. UBAT1570), filed May6, 2004, now pending, the entire contents of which are hereby expresslyincorporated by reference for all purposes.

An embodiment of the invention can include a method and/or apparatus formonitoring the status of and tracking the location of shippingcontainers onboard ship, at the shipping terminal, and duringover-the-road (truck and rail) transportation. Thus, the invention caninclude a true “inter-modal” tracking and monitoring system. This methodand/or apparatus can utilize hybrid spread-spectrum (HSS) communicationsfor robust two-way transmission of data to and from the containeronboard the ship and in the shipping terminal. The phrase hybridspread-spectrum (HSS) as used herein is defined as a combination ofdirect sequence spread-spectrum (DSSS), for example code divisionmultiple access (CDMA), and at least one of frequency hopping, timehopping, time division multiple access (TDMA), orthogonal frequencydivision multiplexing OFDM and/or spatial division multiple access(SDMA), for instance as described by PCT published application No. WO02/27992 and/or U.S. Ser. No. 10/817,759 filed Dec. 31, 2003. Fast HSSis a particularly preferred embodiment where spreading and hoppingoccurs during a bit time (i.e., each bit is spread and hoppedindividually). The invention can utilize cellular and/or satellite datatransmissions for communications during over-the-road transportation.Sensors for monitoring the container cargo status and condition can beincluded in this system. The location of the container can be determinedusing the global positioning system (GPS) during over-the-roadtransportation, and by using more localized radiolocation techniquesutilizing the HSS communication's RF signals. The location and status ofa container can be relayed to a national operations center, whichcombines this data with the cargo manifest in a geographic informationsystem database for monitoring, tracking, managing and displayingcontainer information.

An embodiment of the invention can include a marine asset security andtracking (MAST) system linking robust, long-range RFID technology toGIS-based tracking infrastructure via a global satellite communicationnetwork to create a truly global asset management and cargotracking/visibility system utilizing open systems architecture. The MASTsystem is intended to provide real-time ship/road/rail container andcargo tracking in the context of an open systems architecture for portand supply chain security needs. This tracking technology will create anumber of commercial opportunities, including homeland security, supplychain management, port automation, insurance applications, and potentialrecovery/salvage of lost and wayward cargo in the commercial marketplaceto fund the expansion and adoption of the system. The MAST system effortwill also facilitate the development of new standards and “bestmanagement” practices for tracking and security monitoring ofcontainerized cargo and assets.

The invention can be designed to provide real-time asset, container, andcargo tracking for port security/management needs, and increase safetyof life and property across intermodal transportation networks. Theability to globally track containers in real-time with internalcondition monitoring is essential to securing the supply chain and theport system. The preferred HSS, two-way low-power wirelesscommunications will work well in the context of ship and/or terminalcommunications distances (e.g., range of 300-500 meters) at a power ofapproximately 10 mW.

The RF propagation problems in and around closely stacked steel shippingcontainers dictate the use of extremely robust data-communicationtechniques (e.g., advanced spread-spectrum modulation and diversityreceiving systems) to successfully transmit telemetry signals from theindividual container RF tags to the ship receivers (readers). The goalof highly accurate radiolocation of these containers in large, closelypacked stacks, especially down in ships' holds, will continue to beelusive unless numerous receivers (readers) are distributed throughoutthe yard facilities and over the decks and holds of each ship. If someloss of position resolution can be tolerated in normal operation, thenin most cases the use of carefully engineered container RF tags andinfrastructure components, tailored in their deployment to the specificenvironment (i.e., yard or ship), should provide effective telemetry ofcontainer ID and status data (e.g., door security, temperature) andreasonably accurate container location information (i.e., within onestack position) in the vast majority of specific environmental cases.

A preferred MAST system implementation can use the 2450-2483.5 MHz ISMband to comply with international regulations, particularly for shipsbeing loaded in foreign ports. Further, port facilities overseas willundoubtedly eventually use some sort of RF telemetry for trackingcontainers. If the MAST system protocol fits the internationalallocation in the 2.45-GHz ISM band, it may well be adopted worldwide totrack shipping containers, first in ports and eventually in other venuessuch as rail, planes and trucks. For narrowband system alert signals,beacons, and the like, other ISM band possibilities include the 13.56and 433-MHz slots; the 868-MHz (Europe) and 915-MHz (North America)bands provide somewhat more width for higher-rate and spread-spectrumuse. The data protocol of a commercial embodiments of the invention islikely to be a hybrid or direct-sequence spread-spectrum signal withfairly wide bandwidths (>1 MHz), long code lengths (e.g., >63) forbetter process gain and jamming resistance, and controlled time slottingfor lower collision statistics.

To deploy the MAST system in a marine (yard/ship) environment, severalareas of functionality should be combined in a system. The firstfunctional group encompasses the basic architecture for a sea-basedsystem, which includes (1) communication links; (2) antennas; (3)electronics; (4) container-unit power sources; (5) ship-to-shore systeminterface, e.g., satellite link; (6) container telemetry systemintegration; (7) container location detection [GPS, optimally augmentedby local RF triangulation]; (8) sensors; (9) system central monitoringunits; and (10) container database interfaces. The second functionalgroup includes the port container-yard system, which is largely the samein function as the shipboard setup, except that additional system logicis needed to manage the tracking-system handoff between the ship andyard systems.

1. Overview

Referring to FIG. 1, one or more radio frequency identification tags 101coupled to containers 105 are in bidirectional radio frequencycommunication with a reader 107 on a ship 110. The ship 110 alsoincludes a site server (not shown in FIG. 1) but is in bidirectionalradio frequency communication with a low earth orbit satellite 120. Thelow earth orbit satellite 120 is in bi-directional radio frequencycommunication with an earth station 125.

Simultaneously, another radio frequency identification tag 102 and aninter-modal container 106 (carried by a truck chassis) is also incontact with the low earth orbit satellite 120. It is important to notethat the radio frequency identification tag 102 can also be(alternatively and/or simultaneously) in communication with a cell tower130. While the radio frequency identification tag 102 is depicted to bein direct communication with the low earth orbit satellite 120 and/orthe cell tower 130, it is important to note that the radio frequencyidentification tag 102 could relay through a reader and/or a site serverlocated on the truck chassis.

A network operation center 140 is in bidirectional communication withboth the earth station 125 and the cell tower 130. The network operationcenter (NOC) is in-turn downloading data to a plurality of recipientsincluding in this embodiment Customs, the Department of Defense, theNational Transportation Safety Board, the Department of HomelandSecurity, the United States Coast Guard, the Federal Bureau ofInvestigation and commercial stakeholders.

The marine asset security and tracking (MAST) system, illustrated inFIG. 1, is a wireless (RF)-based communications and sensing/telemetrysystem for tracking and monitoring maritime industry-standard 20-footand 40-foot shipping containers, both during loading, unloading, andtransfer operations at portside dock facilities, as well as onboardships during overseas transport of the containers. This system canprovide a true inter-modal tracking and monitoring system capable ofoperating on ships, railroads, aircraft, over-the-road trucks and withintheir associated terminal facilities, utilizing both local-terminalcommunications systems and other wide-area commercial communicationssystems, including satellite and/or cellular/PCS. This RFID taggingsystem can include RFID tags attached to each shipping container, localsite readers located throughout the ship and in the shipping terminal,one central site server on each ship or in each terminal, and a networkoperations center (NOC) where all data can be collected, consolidated,stored, analyzed and disseminated. The shipping containers can be bothrefrigerated-cargo shipping containers (reefers) and dry-cargo shippingcontainers (dry-boxes). In addition to identifying and tracking thelocation of containers or other equipment fitted with one of the RFIDtags, each tag can be equipped with an (e.g., IEEE 1451) sensorinterface and optional extra serial interfaces to permit the connectionof a wide range of sensors to the RFID tag to monitor the condition ofthe container cargo or other tagged equipment. Sensors which can beconnected to the RFID tag include (but are not limited to) temperature,pressure, relative humidity, accelerometer, radiation, and GPS (globalpositioning system). Additional sensors can be included for conditionmonitoring of machinery, such as refrigeration compressors, or to readfrom the diagnostic data port on some refrigerated cargo containers.

The MAST system has three main operational modes: the first is when theRFID tag is on a ship; the second is when the RFID tag is in a terminal;and the third is when the RFID tag is being transported over-the-road orrail (this includes all times that the RFID tag is not on a ship or in aterminal). A terminal can be considered any local area served by the RFcommunications system. The RFID tagging system can include: a) thenetwork operations center (NOC), which can include the status and dataon all RFID tags and their associated cargo containers (or other asset)and provides this information out to the users; b) the local siteservers (one per ship or terminal), which can manage local-areacommunications (i.e. each ship or terminal) and relay the RFID tag datato a central system server; c) the RFID tag readers, which can receivethe communication from the RFID tags in the local area and relay it onto the local site receiver; and d) the RFID tags.

Referring to FIG. 2, the shore and/or ship communications flexibility ofthe invention is depicted. A first radio frequency identification tag201, coupled to a first container 211, is communicatively coupled tomultiple radio frequency identification tag readers 221, 222, 223, 224located on a ship 230. The multiple radio frequency identification tagreaders 221, 222, 223, 224 are communicatively coupled to a site server235 on the ship 230. The site server 235 is communicatively coupled to asatellite (not shown in FIG. 2) but is in-turn communicatively coupledto the network operation center.

A second radio frequency identification tag 202 coupled to a secondcontainer 212 is communicatively coupled to the multiple radio frequencyidentification tag readers 221, 222, 223, 224 and also simultaneouslycommunicatively coupled to multiple site radio frequency identificationtag readers 241, 242 located on light poles or towers in or around aterminal. The multiple site radio frequency identification tag readers241, 242 are communicatively coupled to a site server 250 associatedwith the terminal. The site server 250 is communicatively coupled to thenetwork operations center via a satellite data link or othercommunications circuit (e.g., a hardwire internet connection).

A third radio frequency identification tag 203, coupled to a thirdcontainer 213, is communicatively coupled to the multiple site radiofrequency identification tag readers 241, 242. It is important to notethat the third radio frequency identification tag 203 is not depicted asin communication with the multiple radio frequency identification tagreaders 221, 222, 223, 224, but could be if their third container 213were physically moved closer to the ship 230.

Still referring to FIG. 2, the shipboard or terminal communications RFIDtags can utilize RF communications to communicate with the RFID tagreaders. The preferred RF communications is a hybrid spread-spectrum(HSS) RF data link operating in the 2.45 GHz band. Radiolocation ortriangulation of the RF signal from each tag can be utilized todetermine the location of each RFID tag.

Referring to FIG. 3, a network operation center 310 is bi-directionallycoupled to a landside site server 320 via an Ethernet or satellite datalink. Simultaneously, the network operation center 310 isbi-directionally connected to a shipboard site server 330 via asatellite data link.

The landside site server 320 is bi-directionally coupled to a firstradio frequency identification tag reader 340, a second radio frequencyidentification tag reader 350 and a third radio frequency identificationtag reader 360. It is important to note that in this embodiment thecommunicative coupling between the site server 320 and the three tagreaders 340, 350, 360 can be any one or more of radio frequencywireless, power line, Ethernet or optical data link. A plurality ofradio frequency identification tags located in the terminal 345 arebi-directionally communicatively coupled to at least one of the threetag readers 340, 350, 360.

The shipboard site server 330 is bi-directionally communicativelycoupled to a fourth radio frequency identification tag reader 370, afifth radio frequency identification tag reader 380 and a sixth radiofrequency identification tag reader 390. It is important to note thatthe shipboard site server 330 is coupled to the three-tag readers 370,380, 390 through one or more of a power line, a radio frequency wirelessor Ethernet data link. A plurality of radio frequency identificationtags located on ship 375 are in bi-directional communication with atleast one of the three tag readers 370, 380, 390.

As shown in FIG. 3, the RFID tag communications can be picked up by theRFID tag readers and relayed to the local site server by one or more ofseveral possible methods: a) RF data link; b) Ethernet; c) power-linedata link; d) optical; and/or e) other(s). Once the tag data is relayedto the local site server, the data can be uploaded to the NOC by eithera satellite-based data link or other internet service provider link(e.g., Ethernet). The local site servers may also generate reports foruse by local personnel, such as the engineers on the ships. Once thedata is uploaded to the NOC, the NOC can communicate back to the taginstructions, verifications and/or queries. The data for any specificcontainer can be made available to any user world-wide with internetaccess and the proper security validation.

Referring to FIG. 4, a network operation center 410 is coupled to afirst cellular or satellite system 420, a second cellular or satellitesystem 430 and a third satellite or cellular system 440. Thebi-directional communicative couplings between the network operationcenter 410 and the systems 420, 430, 440 can be via a phone line or abase station connection. Each of the three systems 420, 430, 440 isassociated with a subset of a plurality of radio frequencyidentification tags outside of local area (RF coverage) zone 450. Thebidirectional communicative coupling between the three systems 420, 430,440 with their respective subset of the RFID tags outside of local-areazone 450 can be via a cellular or satellite data link.

For over-the-road and rail communications, as illustrated in FIG. 4, theRFID tags can communicate to the NOC by cellular or satellite datalinks. The preferred method is direct satellite communications, sincecellular will not give world-wide coverage. The satellite or cellularsystem can relay the RFID tag data to the NOC through a base station(satellite) connected to the NOC or through a modem bank (cellular)connected to the NOC. Over-the-road operation can include all operationswhen the RFID tag is not onboard a ship or in a terminal (any local areaserved by the RF communications system). A GPS receiver in each tag canbe utilized during over-the-road transportation to track the movement ofand the location of the container. It is preferred that the containersare not stacked during over-the-road operation. If a tagged container isstacked with another container on top of it, as is possible on some railcars, the satellite or cellular modem data links and the GPS system maynot function. It is possible for another tagged container on the top ofa stack to act as a repeater or relay (extender) for the firstcontainer. In more detail, the first container can utilize the HSS RFcommunications when its other methods fail. The second container canreceive these communications with its HSS RF receiver and then relaythem to the NOC utilizing its satellite or cellular modem data link.

2. RFID Tag Description

Each RFID tag can include four main functional blocks; (1) amicroprocessor control subsystem; (2) a sensor subsystem; (3) acommunications subsystem; and (4) a power supply subsystem. FIG. 5 showsa block diagram of an RFID tag.

Referring to FIG. 5, a radio frequency identification tag 500 includes amicroprocessor control subsystem 510, a power supply subsystem 520, asensors subsystem 530 and a communications subsystem 540. Themicroprocessor control subsystem 510 includes an input/output interfacescircuit 511. A microprocessor circuit 512 is coupled to the input/outputinterfaces circuit 511. A flash memory circuit 513 is coupled to themicroprocessor circuit 512. A random access memory circuit 514 is alsocoupled to the microprocessor circuit 512. The microprocessor circuit512 is coupled to the power supply subsystem 520 via a power line 515.

The power supply subsystem 520 includes a power management modulecircuit 521. An AC to DC power circuit 522 is coupled to the powermanagement module 521. A battery 523 (e.g., lithium ion) is coupled tothe power management module 521. An alternative power source 524 iscoupled to the power management module 521. The power supply subsystem520 provides power to the sensors subsystem 530 through a set of powerlines 525. The power supply subsystem 520 provides power to thecommunications subsystem 540 through a set of power lines 526.

The sensors subsystem 530 includes a serial interface 531 coupled to theinput/output interface circuit 511 of the microprocessor controlsubsystem 510 through line 532. A temperature sensor 533 is coupled tothe serial interface 531. A relative humidity sensor 534 is coupled tothe serial interface 531. A door ajar sensor 535 is coupled to theserial interface 531. Other sensors 536 (e.g., ionizing radiationsensors) are coupled to the serial interface 531. The sensors subsystem530 includes a GPS module 537 coupled to the input/output interfacecircuit 511 of the microprocessor control subsystem 510. The sensorssubsystem 530 includes a refer unit data port 538 coupled to theinput/output interface circuit 511 of the microprocessor controlsubsystem 510 via an interface converter circuit 539.

The communications subsystem 540 includes a local/serial communicationcircuit 541, a cellular modem module 542, a hybrid spread-spectrum radiofrequency module 543 and a satellite module 544, all of which arecoupled to input/output interface circuit 511 of the microprocessorcontrol subsystem 510 through line 545. One or more antennas 546 arecoupled to the cellular modem module 542, the hybrid spread-spectrumradio frequency module 543 and/or the satellite module 544.

Microprocessor Control Subsystem: The microprocessor control subsystemcan operate as the controller for the RFID tag. It can interface withthe communications modules, with the sensor modules, and the powermodules. The microprocessor can utilize both non-volatile and volatilememory to store the system software, system commands, and sensor data.

Sensor Subsystem: The sensor subsystem can utilize IEEE 1451-compliantprotocols for communicating with one or more sensor modules. This allowsthe future addition of any sensor as long as it is compliant with the1451 protocol. Some of the basic sensors, such as the GPS and the reeferdata port reader, may utilize serial communications ports on themicroprocessor. Sensor types that may be part of the RFID tag caninclude temperature, relative humidity, radiation, biological, chemical,accelerometer, door switch, intrusion, etc.

Communications Subsystem: The communications subsystem can allowmultiple different types of communication's links to be incorporatedinto the tag platform. They may connect through, for example, a serialport or an Ethernet port.

The basic communication's modes can be as follows:

RF Communications—the RF communications can take the form of any numberof available wireless communications protocols. However, the preferredmethod is a hybrid spread-spectrum protocol. This protocol provideshigher reliability, lower power, and more robust communications thanother wireless techniques. The RF communications can be intended for useprimarily when the tags are located on a ship or in terminal (local-areacommunications).

Cellular/PCS Communications—standard commercial cellular analog ordigital modems, such as CDMA or GSM, can be utilized by the tag forover-the-road (truck or rail transportation) communications. However,there is not a standard cellular infrastructure installed worldwide.Therefore, each tag could require several different protocols to be ableto operate in more than just a limited market area. In addition, thetags are likely to travel through areas that have no cellular coverage.

Satellite Communications—utilize a satellite-based communicationsnetwork to provide an over-the-road communications link that canfunction anywhere in the world. This provides simpler, more robust, andmore secure communications system as an alternative to, or in additionto the cellular system. A preferred embodiment can use a Low-Earth Orbit(LEO) satellite network system.

Local Communications—Each tag can have a serial port used fordevelopment, troubleshooting, and/or initial setup. The serial port maytake the form of, for example, RS232, USB or IrDA (infrared).

Power Supply Subsystem: The power supply subsystem can provide power toall the other subsystems. The sources of power that may be utilizedinclude battery, AC power (e.g., from the refrigeration power supply onreefers) and other power scavenging and/or generating devices such as aphotovoltaic, a vibrational transducer, an electrostatic charger, aradio frequency power rectifier, a thermoelectric generator and/or aradioisotope decay energy recovery device. For RFID tags located onassets other than containers, DC power from the assets electrical systemmay also be utilized. The power supply subsystem can convert the voltageof the power source to the required voltage for each subsystem. It alsocan perform power management functions to monitor battery condition andpower source availability.

3. RFID Tag Reader

The RFID tag readers relay the RFID tags' communications to (and from)the site server. The RFID tag readers can be similar to RFID tags, butwith different communications modules, and optionally no sensors. TheRFID tag readers can communicate with the RFID tags through a local RFcommunications module (preferably using the HSS protocol). The RFID tagreaders can communicate with the site servers by one of several possibletechniques: wireless RF communications (preferably the HSScommunications at a frequency other than the RFID tag communications,such as for example at 5.8 GHz), wired communications (such aspower-line communications, Ethernet or serial), and/or opticalcommunications (such as by fiber optic or line-of-sight lasercommunications).

Referring to FIG. 6, a plurality of inter-modal shipping containers 610are stacked in a two-tier high array. Each of the inter-modal shippingcontainers 610 includes a radio frequency identification tag 620. Aplurality of tag readers 630 are located at the ends of open aislesdefined by the two-tier high array.

Another optional feature of the MAST system is the use of “hand-held(portable) readers” for reading the RFID tag data and cargo manifestdirectly from the container. The hand-held reader can be used byCustoms, Coast Guard, shippers, or other certified groups to ascertainthe contents of a container and its cargo status (sensor data, movementhistory etc.). The hand-held reader can be located and then operatednear the container. The appropriate identifying code (or perhaps barcode) can be entered into the hand-held reader, and then RFcommunications used for the hand-held reader to communicate with theRFID tag. The RF communications can preferably utilize the HSScommunications utilized for the local terminal and ship communications.The RFID tag would then download to the hand-held reader the containermanifest (from the manifest stored on the RFID tag or downloaded fromthe NOC via a uplinked request from the RFID tag) and a trip log of thecontainer sensor(s). This trip log could contain history reports for allsensors, any sensor alarms (including container instrusions, temperatureexcursions, etc.), and a history of the container's specific geographicroute.

The hand-held readers can also be used to upload a container's cargomanifest (this could also be done by using a portal). As the containeris loaded, bar codes or other types of packaging-type RFID tags can beread into the hand-held reader. From the hand-held reader (or other typeof RFID reader), the cargo identifiers can be loaded into the containermanifest on the container's RFID tag and then uploaded to the NOC.

An alternate approach would be to utilize an IrDA (infrared) data porton the container. The hand-held reader would then be pointed at the IrDAport and communications established. The data download would then be thesame as above.

4. Site Server

The site servers can receive the RFID tags' data from the RFID tagreaders. The site servers can send the RFID tag data to the NOC. Thesite server can also perform local analysis of the RFID tags' data andmanage the multi-access aspect of the invention that allows for tens ofthousands of tags to be in a terminal or on a ship. The site servers caninclude three main subsystems: (1) a computer-based server and systemcontroller; (2) an RFID tag reader communications subsystem whichincludes the same communications modules as the RFID tag readers forcommunicating with the RFID tag readers [i.e., they can have wireless RFcommunications (preferably the HSS communications at a frequency otherthan the RFID tag communications, such as at 5.8 GHz), wiredcommunications (such as power-line communications, Ethernet or serial),or optical communications (such as by fiber optic or line-of-sight lasercommunications)]; and (3) a NOC communications subsystem which canutilize hardwired, cellular, optical or satellite communicationsmodules.

5. Network Operations Center

The Network Operations Center (NOC) can be the information center for aworld-wide Maritime Transportation Control System. All RFID tag datafrom all RFID tags located around the world can be relayed to the NOC bythe local site servers or via direct cellular or satellitecommunications. The NOC collects, stores and disseminates RFID tag data,including location, sensor data, and RFID tag status.

The invention can include the merging of technologies in a centraloperations center architecture including: global positioning systems;radio frequency identification (RFID) based tracking system for assetsand cargo containers; globally available commercial satellite andInternet communication systems; geographic information systems (GIS) andreal-time logistical analysis capabilities; fault-tolerant systems toprovide hardened continuous data flow to private sector asset and cargoowners, relevant state and federal governmental entities (Coast Guard,TSA, Customs, NTSB, and DoD, etc.), and local first responsestakeholders (law enforcement, fire departments, local government); andexisting federal systems and commercial programs for asset and cargotracking.

The use of a geographic information system (GIS) in the NOC will allowfor the analysis and presentation of asset location in a variety offormats from simple web-browser based Latitude/Longitude reports tomap-based city/state/zip/country information. This system can providethe ability to monitor and profile assets in real-time based on criteriaspecified including geographic patterns. This approach also provides forthe incorporation of real-time logistical analysis regarding themovement of assets. The long-term goal of the GIS development is tocreate an information infrastructure capable of analyzing the movementof commodities and assets throughout the supply chain and intelligentlyprofile containers including geographic patterns.

The RFID tag data can be integrated to a centralized GIS-based trackinginfrastructure via a global satellite communication network to createthe MAST system. A preferred embodiment of the MAST system inventionutilizes one or more global satellite networks.

Satellite networks provide the ability to track and monitor assetsglobally in real-time with the ability to concentrate all theinformation effectively in one location. This provides advantages forsecurity, fault-tolerance, data back-up/archiving, and maintenance. TheNOC can integrate the geographic information systems (GIS) technology,satellite communications, global positioning systems, RFID (electronicseals, etc.), and the Internet in an open systems architecture to createa real-time tracking and asset management system. The NOC can provideone single location for real-time logistical support for the globalmanagement of mobile assets using a web-based tracking system that willallow individuals or organizations to manage assets in real-time via theInternet with strict information protection protocols (e.g., loginand/or encryption). The information can be distributed to relevantparties through secure transactions on a need-to-know basis thusprecluding the use of the system to target assets for theft.

The NOC can have one or more of the following resultant operationalcapabilities: 1) real-time, global ship location tracking with detailedhistory of passage; 2) tracking container location and condition withtampering notification and internal environmental and radiation status;3) early warning/threat identification of ships and containers arrivalin US waters and ports with an audit trail that identifies potentialthreats, risks, and responsibilities; 4) detecting and monitoringsuspicious shipping activities (unscheduled port calls, etc.) andidentify long-term patterns of activity at both ship and containerlevel; 5) secure data to (and/or from) the Department of Defense, USCoast Guard, US Customs, Department of Homeland Security, as well aslocal “first response” law enforcement agencies for homeland security,port security, smuggling, and theft concerns; 6) secure data to (and/orfrom) shippers and ports to plan and manage cargo arrival anddistribution on an as-needed basis; 7) system for comprehensive port,ship, and container management and “fast-track” protocols for Customsinspection; 8) real-time monitoring capability for refrigerated,critical, and HAZMAT cargo; 9) remote control tower(s) for marineindustry to maximize efficiency and central point of contact forimportant information (e.g., rules, regulations, weather notices,notices to mariners, etc.); and 10) integrate intermodal warehousing,port, ship, road, and rail supply chain management and securityapplications on a global scale.

6. Multiple-Access

The multiple access approach described herein enables a multiple accessnetwork that can operationally accommodate roughly 10,000 RFID tagsspread over a terminal or ship located in an environment that mayinclude upwards of 90,000 additional RFID tags (potential interferencesources) located in/on nearby terminals or ships. This multiple-accessdesign can utilize one or more of CDMA, FDMA, TDMA and/or SDMA (spatialdivision multiple access) to achieve these requirements. The RFID tagscan each report electronic identification codes, sensor data, andlocation information to an array of RFID tag readers that form either aperimeter around or a grid throughout the terminal or ship. The RFID tagreader locations may utilize the existing infrastructure of lightingtowers that are currently in the yards. These RFID tag readers cancoordinate the data from the tags and report all useful data to a nearbysite server. The site server can then relay significant events andsensor data to the NOC. A description will follow of the terminal/shiparea communications with a focus on the RFID tag to RFID tag readerlinks.

General Strategy

The following describes elements of a preferred overall communicationsstrategy. An embodiment of the invention can include a combination ofCode-Division Multiple Access (CDMA) utilizing both Direct SequenceSpread-Spectrum (DSSS) and Frequency-Hopping Spread-spectrum (FHSS),Time-Division Multiple Access (TDMA) and Spatial-Division MultipleAccess (SDMA) can be used for the tag-to-reader link. An embodiment ofthe invention can include a reader-to-server link utilizing a differentfrequency band (e.g. 5 GHz). An embodiment of the invention can includebi-directional communications that can enable power control to beemployed to optimize CDMA and SDMA methods. An embodiment of theinvention can include independent terminals (yards) in close proximitybeing given distinguishable groups of spreading codes from proximateneighboring yards. An embodiment of the invention can include an optionof sub-dividing yard into micro-cells.

The following describes key performance parameters of the abovedescribed preferred overall communications strategy. A site server canreceive updates from 10,000 proximate tags at least once every 100seconds with 99.99% probability of success. The network that includesthe site server can have the ability to “ignore” up to 90,000semi-proximate tags. High-priority message(s) from the tag(s) can besent within 1 second of delay.

Implementation

The following implementation analysis includes the followingassumptions. One thousand bits are used from each node once every 100seconds. Offset-Quadrature Phase-Shift Keying (OQPSK) modulation with a5 MHz bandwidth and nearly constant-envelope signals is used. Sixteen ormore non-overlapping hop frequencies with managed overlap fraction.Length-63 spreading codes for Direct Sequence are used.

Based on the above explicit assumptions, the 1000 bit (125 byte) packetswill be transmitted once every 100 seconds from each of the 10,000 nodesat a bit rate of 80 kbps with a chipping length of 63. Thus, theembodiment of the invention has a chipping rate of about 2.5 Mbps whichtranslates to a spectral bandwidth of about 5 MHz with OQPSK modulation.It is assumed that the RFID tag readers will need to communicate witheach RFID tag about once every 100 seconds. Therefore, 10,000 RFID tagstranslates to an average of 20,000 packets every 100 seconds. These20,000 packets will be multiplexed into 4000 time slots (25 ms long) and32 CDMA users (combination of 63 length codes with 16 hops—assuming themaximum simultaneous users is approximately square root of chip lengthtimes square root number of hops.)

The perimeter RFID tag readers can use directional antennas aimedbetween rows of containers for RFID tag communications. Directionalantennas operating in a different frequency band (e.g. 5 GHz) [oralternatively, power-line communications] may be used fortower-to-tower/server communications. Depending upon yard size and otherenvironmental parameters, the towers may also be required to providerelayed communications

The main functions of the RFID tag readers can be to capture informationfrom all of the RFID tags and then relay this information to the siteserver. They may coordinate with each other in a fashion that optimizesthe multiple access plan for upwards of 10K tags, or they may onlycommunicate directly to the site server. For example, if several readersare capturing the data from a single RFID tag, then the readers cancooperatively determine the lowest power level at which at least onereader can reliably communicate with the RFID tag.

Power Control

As mentioned above, power control can be used to optimize the networkcommunications. Of course, power control is desirable to a great extentby the use of DS-CDMA. This multiple access approach can includeprotocols for network discovery, power back-off, and interferencemitigation techniques that all involve controlling the transmitted powerfrom the RFID tag.

Re-Transmission Redundancy

The above analysis assumes that the system needs to hear from every RFIDtag at a rate of once every 100 seconds and that about 1000-bit messagesare sufficient. This includes a conservative estimate for inter-packetguard time of 100% of packet length. In the above example, packets wouldbe approximately 12.5 ms long and the average guard time would be about12.5 ms also. This guard time is very conservative and can probably bereduced by upwards of 90%, thus enabling almost another doubling of thethroughput or redundancy. A subsection of the guard time is to be usedfor “emergency” events in a CSMA fashion. Furthermore, most applicationswill not require 100-second update rates; therefore, successive timeslots during the next 100-second cycle can be used to re-transmit badpackets. For instance, an update rates of once an hour, or every secondor even third hour could be sufficient for most applications.

In order to perform power control as discussed above and to carry outthe typical duties of channel assignment and network optimization, astrict flow control should be established for the boot-up sequence ofall nodes. This following description in conjunction with FIGS. 7-8(flow charts) present a design example of that process.

Discovery Process

As shown in FIG. 7, the nodes will boot-up on a system control (default)RF channel. The nodes will cycle through a small set of “pilot” channelsuntil they establish a link with one of the RFID tag readers. This loopis necessarily endless until or unless successful communication isestablished with a reader (or another tag if an alternative tag-to-tagapproach is available in a given system). An embodiment of the inventioncan include stepping the power up and/or during this process.

Referring to FIG. 7, an exemplarily tag boot-up sequence can begin witha tag turn on step 710. At step 720, the tag sets a default receivercode. At step 730, the tag listens for a pilot transmission signal froma tower. At step 740, if a signal from a tower is identified, then thetag proceeds to a transmission-to-network communications 750. If a toweris not identified, then the tag determines whether a time-out period haselapsed at step 760. If the time-out period has not elapsed, then thetag continues to attempt to identify a tower. If the time-out period haselapsed, then the tag proceeds to a step 770 including settingalternative receiver frequency codes. After setting an alternativereceiver frequency code, the tag then proceeds to step 730 and againlistens for a pilot transmission from a tower.

During the discovery process, it can be desirable to minimize the numberof tags transmitting at a given time. This can be accomplished by havingthe reader node control the discovery process. The reader will send outan ID Request that prompts all tags within its range to transmit in agiven order on a given temporary code (see Network ID Transmit Orderbelow). Then the reader will start receiving and processing messagesfrom the tags. After the first cycle of node identification iscompleted, the reader will send a message to the tags acknowledgingreceipt and assigning both a network ID and a time slot allocation forthe tag. The cycle will be repeated, with the qualification that alltags having network ID assignments (associated with that reader ID) willnot acknowledge the ID Request message. The invention can includeprotocol for resolving conflicts, etc.

Network ID Transmit Order

The reader can request that all tags that are able to decode its IDRequest (and which have not been previously logged by that reader)transmit a 5-ms message x times 10 ms after receipt of the request wherex is the 3 least significant digits of the tags UUID. (For instance, atag having a UUID of 12345678 could wait 6,780 ms before transmitting tothe reader.) In addition, the tag can use the next 2 higher digits (inthis example 45) to select a combination of FH and DS codes. Thus, areader should be capable of handling 100,000 tags unambiguously.

Once the RFID tag and the RFID Tag Reader have established a link, thereader will assign the RFID tag a code and frequency combination thatmakes it part of an optimized network. This process is shown in FIG. 8.

Referring to FIG. 8, upon a transmission from communications discovery810, the tag obtains or adopts a default transmission frequency code atstep 820. At step 830, the tag sends the default transmission frequencycode to the tower. At step 840, if the tower acknowledges the defaulttransmission frequency code, then the site server will assign to the taga code frequency and time slot at step 850. If the tower does notacknowledge at step 840, then the tag will proceed to step 860 where itdetermines whether a time-out period has elapsed. If the time-out periodhas not elapsed, then the tag returns to step 840 and will continue toawait acknowledgement from the tower. If the time-out period has elapsedat step 860, then the tag will proceed to a step 870 where analternative transmission frequency code will be obtained or adopted. Thetag then proceeds back to step 830.

Packet Structure

This section focuses on the portions of the packet dedicated to ensuringrobust communications such as the preamble and errorcorrection/detection coding. The payload of the packet can be any usefulpayload (e.g., identity, location, dosimetric, etc.).

Since the preferred waveform utilizes frequency hopping as well asdirect sequence spread-spectrum, the preamble can have two portions: a64-bit constant frequency DSSS portion and then a 63-bit hybrid FH/DSSSportion. The receiver correlator can search the beginning of thetransmitted waveform for autocorrelation peaks on a known frequency.Once the receiver has derived the location (in time) of the “bit” edges,it can start hopping its carrier frequency. The transmitted waveform canstart hopping at the start of the second portion of the preamble thatcan act as a data delimiter word. The receiver can re-establishsynchronization with the hopping sequence at the start of this second(63-bit) sequence. This allows the receiver to miss upwards of 5 bits ofthe sequence and still successfully find the start of the data payload.A CRC word 32 bits in length will complete the packet and can be used toensure the integrity of the actual data payload.

Direct Sequence Spread-Spectrum

The DSSS assignments can be chosen from a Kasami code generator thatproduces about 520 codes of length 63. Only about 32 codes can be in usewithin a given cell, within a given time slot. However, utilization ofthis large set of codes makes the code assignment processes easier tomanage.

Frequency Hopping Spread-Spectrum

During any given packet slot, some of the channel orthogonality can beachieved via frequency hopping assignments. Since, the assumed RF tagspectrum is about 5 MHz and the Industrial, Scientific, and Medical(ISM) band at 2.45 GHz is 80 MHz, only 16 hopping center frequencieswould in this example be utilized. While hybrid spread-spectrum ispreferred primarily to improve the robustness of individual linksexposed to a harsh multi-path environment, it can also be advantageouslyutilized to increase the number of simultaneous users occupying a timeslot. If timing synchronization for this system in a particularimplementation is not sufficient to support the high-speed hoppingscheme, then the DSSS spread-spectrum alone can be used fordistinguishing multiple simultaneous users.

7. Marine Systems Observations and Analyses

The size of the ship terminal facility will strongly affect theconfiguration of the shore-side RF system (i.e., number and distributionof receivers) required to track containers throughout this facilityexpanse. The light poles at a terminal are preferred locations forfacility receivers and transmitters (or transceivers).

Shipboard RF container-monitoring receiver(s) could be sited on the mastat the ship's bow end. It is important to note that containers are notalways stacked to a uniform height on deck or in a very consistentdistribution. RF propagation into or out of covered holds (steelhatches) may be essentially nil; therefore, it may be necessary toprovide RF system receiver(s) inside the holds to facilitate monitoringof containers there.

In a loaded ship, containers are often stacked above-deck right up tothe edges of the hull. The bridge wings and masts, can be used formounting RF infrastructure components for the MAST system. Gaps betweeneach row and stack of containers can permit an RF signal of suitablewavelength to bounce back and forth before finally reaching the edge ofthe ship. It can be desirable to place a system antenna at each end ofthis space, along the periphery of the ship, to achieve consistentcoverage of all the containers above deck.

Containers are typically stacked tightly in the hold. The containersslide down vertical retaining rails attached to the ship's structure.The metal bulkheads effectively compartmentalize the areas around theends of the containers, further hindering RF propagation from thecontainers within the hold. Once the hatch is placed over the hold, afairly good Faraday cage is formed and very little RF can enter orleave. Therefore, it may be necessary to install some in-hold RFinfrastructure (i.e., receivers and associated data links back to thecentral monitoring station on the ship's bridge) if near-real-time(e.g., daily) telemetry is required from containers stacked down in theholds. The container locking mechanism ensures a 2- to 3-in. gap betweenthe tops and bottoms of the stacked containers. The roughly 2- to 3-in.space between the tops and bottoms of containers should be sufficient toprovide an RF path (at suitable frequencies) between the containers. Thecorresponding space between the sides of the containers typically variesfrom 0.5 in. to about 2 in. This arrangement can create an ohmic (lossy)and/or capacitive connection at radio frequencies between thecontainers, which may somewhat impair the signal propagation out of thestack.

Referring to FIG. 9, a plurality of inter-modal shipping containers 910are arranged in an orthogonal array. A radio frequency identificationtag 920 is depicted on the top of one of the inter-modal shippingcontainers 910. A plurality of readers 930 are located at the ends ofthe aisles formed by the plurality of multi-modal shipping containers910.

FIG. 9 depicts a plan-view of a group of tightly stacked containers(nominally 40-footers) as they might be arranged on the deck of a shipor on the ground within a terminal yard. A single RF emitter(represented by a radiating red dot in the diagram) can be mounted nearthe center of the top of a container. Because the containers'undercarriages and top side rails tend to channel the signal lengthwise,most of the RF energy will leak out of the two ends of the containerinto the adjacent aisles in both directions (up and down on thediagram). These signals will bounce between the ends of the containersbounding the aisle until they emerge at the edges of the array,suffering moderate losses and significant waveshape distortion. Fairlywideband (i.e., several-MHz) spread-spectrum signals with high immunityto scattering and multipath-type distortions are likely to be receivedbest. Of course, the invention is not limited to any particularcontextual configuration.

Potential RF receiving and/or transmitting locations are denoted in FIG.9 by dots at the ends of the aisles. Although each dot could represent adiscrete antenna, a more practical, robust configuration might employshort pieces of “leaky coax” cables to span the aisles and standardlow-loss coax sections in between. To afford better physical protection,the “leaky” cable could be housed inside sections of heavy-walled PVCpipe, which presents relatively low losses at up to a few GHz infrequency; the standard cables could be run in PVC or even metal conduitfor the best crush resistance, since the conventional coax is fullyshielded. These receiving and/or transmitting location systems could bemounted (semi)permanently at the ship's periphery, at or near decklevels, and perhaps even on handrails or other convenient structures.There is typically a personnel catwalk between rows of containers oneach side of the cargo holds. It is possible to locate RF systemantennas for container telemetry links at appropriate spots on catwalkassemblies.

The precise locations and mode(s) for mounting these antenna componentswill be highly dependent on the detailed specifics of an individualship's construction. In the case of containers in one of the ship'sholds, the leaky-coax cable could be installed along the side wall, inroughly the same vertical plane as the container guide rails. In bothinstances, the orientation of the leaky-coax cable should be maintainedto provide the most efficient energy transfer with respect to thepolarization and orientation of the antennas on the containers. Forexample, for horizontal container RF launchers, the cable should alsorun approximately horizontally to maintain relatively low couplinglosses in the container-to-local-receiver RF links (assuminghorizontally polarized container antennas).

Other major system design considerations lie in the selection ofappropriate RF operating frequencies. Legal and licensing constraintsfavor the use of allocated license-free bands such as the currentIndustrial, Scientific, and Medical (ISM) bands of 13.56, 27.55, 433,902-928, 2450-2483.5, and 5725-5825 MHz and the so-called UnlicensedNational Information Infrastructure (U-NII) bands of 5150-5250 and5250-5350 MHz in the United States and the rest of North America [and/orsimilar allocations in other parts of the world]. The first threesegments are narrow in width (well under 1 MHz), while the latter fiveare intended for various forms of spread-spectrum signaling.

Although the narrow bands may support very low-rate data transmission,their capabilities for radiolocation and highly robust links aredecidedly limited. On the other hand, the spread-spectrum bands permitsignificantly higher RF power levels and will support much moreresilient modulation techniques. Overall, the 902-928 MHz band willprovide the greatest range, but the 2450-2483.5 MHz band is essentiallyuniversal and can be utilized (at least in part) throughout the world.There are several emerging RF standards in the general fields ofradiolocation and telemetry. The HSS protocol is already explicitlypermitted in the ISM and U-NII bands by current Federal CommunicationsCommission rules.

The flexibility of multi-band and/or multi-protocol devices forcontainer tracking can also be used by the invention, although thepenalty in tag cost, power efficiency, and complexity can be fairlyserious. The invention can utilize highly integrated multiple-band RFdevices (including transmitter and receiver electronics, filterstructures, and antennas) that are preferred for worldwide versions ofthe MAST system concept.

An additional consideration is the specific type of RF systemarchitecture required to achieve the desired level of functionality. Abidirectional data-telemetry system will permit a more sophisticatedtag-device feature set, including accurate RF-signal power control;remote reprogrammability; individual tag (addressable) queries;multi-tag relay capabilities; ad-hoc dynamic tag-to-tag data routing toovercome RF path blockages and nodes with low-battery conditions; andnetworking tasks, such as rolling security codes, remote softwarechanges/updates via the network, and node-status inquiries. The overallnode power efficiency and energy utilization is also usually optimumwith a bidirectional protocol, resulting in the longest possible batterylifetimes and most timely node-alarm reporting and diagnosiscapabilities. Of course, the penalty for this type of RFID tag node isincreased complexity and cost increase due to the presence of an onboardRF receiver, but the additional acquisition cost may well be more thanoffset by the increased battery life and, therefore, reduced maintenanceinterventions by ships' crews or other maintenance/service personnel.

By contrast, the basic unidirectional network comprises autonomous tagsthat generally operate in a “dumb chirper” mode, in which the tagssimply burst their data out to the system infrastructure receiver(s) atpredetermined intervals. These transmission intervals may be regular,randomized, slot-randomized, or even altered by the nature of the tag'sdata. For instance, a highly preferred embodiment is a “smart” tag thatwould simply omit transmissions of redundant data, instead sending onlynew, changed readings. A slight modification to this protocol wouldinvolve the straightforward insertion of a few additional transmissionsat a selectable interval to reiterate the true data value (in case achange was inadvertently missed) and convey some basic statusinformation to confirm that the node is still operating properly.

A third type of telemetry-system architecture would support thestrategic (or even happenstance) mixing of bidirectional andunidirectional tags as dictated by a particular implementation scenario.This format permits significant flexibility in selection of the tagtypes, though at some cost in overall RF system performance andgenerally reduced tag battery lives. Although the preceding descriptionsare based on nominally single-band network setups, even more flexibilityand higher performance can be obtained in a multi-band system, albeit ata significant cost penalty (principally in the total price of all thetags). In all these instances, the use of the HSS technique affordsadvantages in bit-error rates, loss of packets, collision rates, RFpower efficiencies, and apparent interference levels toward otherfacility RF systems, particularly those sharing the same general bands.An embodiment of the invention can include mixing bidirectional relaytags with “dumb chirper” tags in one system.

A refrigerated container (“reefer”) typically includes a 3-phase powercable that plugs into an above-deck outlet fed from the ship'selectrical distribution system. In general, the reefer-monitoringapplication is particularly important because of the high values of thecooled cargoes (e.g., pharmaceuticals, perishable foods, and medicalsupplies). The current practice is for ship personnel periodically tomanually monitor and record (i.e., with pencil and clipboard) a singleinternal temperature while at sea; any deviations are reported to theship's engineering crew. In addition to the internal temperature(perhaps at several spots), additional data such as relative humidity,compressor pressures, coolant flows, electrical supply voltage/current,and container integrity (door breach) can be acquired via automaticmonitoring and alarm telemetry. This information could add greateconomic value to an embodiment of the invention by providing earlywarnings of refrigeration failures, thereby facilitating rapid repairsand avoiding costly cargo spoilage. This telemetry could be handled viaRF techniques, as discussed earlier, or through robust data transportover the ship's ac power system. Even more advanced methods-such aselectrical signature analysis can more accurately assess the conditionsof operating compressors, fans, pumps, valves, and other motor- andsolenoid-driven loads and provide a high level of real-timecondition-monitoring capability for critical shipboard equipment.

8. Analysis of RFID Tagging System Communication Requirements

Perhaps the paramount technical issue in the development of a workableRF-based tagging system protocol is the need for highly reliable,robust, low-power RF communication links, particularly between thesensor/ID tags mounted on the containers and the facility or shipboardreceiver infrastructure. A telemetry approach using a hybrid(direct-sequence/frequency-hopping) spread-spectrum transmissiontechnique to simultaneously improve RF tag performance markedly (re:data and locational accuracies) and reduce RF interference generationand susceptibility with respect to other tags and facility RF systems ispreferably to be used. As noted above, the phrase hybrid spread-spectrum(HSS) as used herein is defined as a combination of direct sequencespread-spectrum (DSSS), for example code division multiple access(CDMA), and at least one of frequency hopping, time hopping, timedivision multiple access (TDMA), orthogonal frequency divisionmultiplexing OFDM and/or spatial division multiple access (SDMA), forinstance as described by PCT published application No. WO 02/27992and/or U.S. Ser. No. 10/817,759 filed Dec. 31, 2003. Another benefit ofthis technique is in the area of power utilization-the HSS protocolincorporates features to facilitate power savings by limiting the numberof RF transmissions from each tag and concurrently dynamicallyminimizing collisions with other tags, thus reducing the requirementsfor tag data messages (e.g., re-transmission(s)) to an (absolute)minimum. Another key system operational issue is that of internal powermanagement for the tag subsystem (i.e., logic, RF circuitry, andsensors).

To maintain useful battery-recharge intervals, both thecommand-receiving and data-transmitting functions of the RFID tags canbe performed on a very low duty-cycle basis, since receive-system powerconsumption levels often are not very much lower than those of thetransmitters. In addition, all data from the smart-tag sensors can beprocessed to eliminate redundant transmissions altogether. Finally,low-battery warnings can be transmitted as needed (embedded in tag databursts) to the facility receiver(s) to ensure proper tag operability(i.e., data access and tag location), preferably at all times.Alternative tag-energizing options can include local passive-stylepowering via an interrogator wand, onboard photovoltaics, or otherenergy sources. Some of the system protocols described above assumebidirectional transmission to the container tags, but it is feasible toconsider unidirectional “dumb-chirper” tags for some systemimplementations that do not require on-demand tag interrogationcapabilities.

Pertinent port (shoreside) facility-system design issues includeplacement of the distributed transceiver/radiolocation units, internalinfrastructure signaling options, and the use of RF repeaters to provideadequate and consistent spatial RF coverage throughout the facility. Thebasic infrastructure may use twisted-pair wires, coaxial cables,power-line RF transmission techniques, or wireless RF transceivers totransfer data between the facility transceivers and the centralcontainer monitoring and control point. Yard RF transceivers will mostlikely be mounted on existing structures, although such an arrangementwill depend largely on the specific setup of the terminal. Thecorresponding shipboard RF infrastructure will be much more constrainedby the layout of the vessel and the limited opportunities for optimallysiting the RF equipment for best coverage. Numerous compromises can beaccommodated, since the fixed RF gear may need to operate from ship'spower and may have to be mounted in locations out of the way of normalshipboard operations and maintenance activities. To this end, it ishighly desirable to handle RF infrastructure data communication via theship's AC power-distribution system; doing so will provide a physicallyprotected path and obviate the need to run additional cabling throughoutthe ship when retrofitting a system embodiment of the invention into thevessel.

9. Requirements for Container Monitoring and Sensors

Container location tracking can require different solutions for shiptransport versus rail and truck transport. Onboard a ship, a GPS-basedtag alone may not be viable unless combined with a triangulationfunction. In more detail, GPS is a line-of-sight location system inwhich the receiver must be able to “see” three or more satellitesources. Containers buried in stacks on deck or inside a ship's holdwill not be able to obtain the required line-of-sight signals to use theGPS satellite sources; adding a local GPS repeater onboard the ship maynot solve this problem either. Even if GPS signals of adequate strengthare received and repeated, the high levels of local RF multipathreflections in the stacks may cause major uncertainties in the locatingaccuracies and render the results generally unacceptable. Further, therequirements for extremely low tag operating powers will almostcertainly exclude individual GPS receivers even where adequate satellitereception might be possible. The preferred on-board solution includesthe use of a local triangulation system. Using a local triangulationsystem tailored for the local onboard environment can permit the bestpossible container-location performance. Because of the severe multipathreflections and limited (power-constrained) tag transmitting times, sucha system may not in all instances be able to give an exact containerposition, but rather give just the approximate location, probably within±1 container up/down, fore/aft, and port/starboard. In a great majorityof cases, this level of accuracy should be quite adequate.

For shipboard triangulation, multiple receivers may be required. Thelack of line-of-sight propagation from a given container to a fixedcentral receiver will make a suite of receivers necessary to localizethe position of the container transmission for containers stacked abovedeck. In addition, it will be difficult to localize containers in holdsbeyond identifying which hold they are in. Because of the overwhelminglevels of multipath and obstructions to the RF signal paths, each holdcould require up to one receiver and antenna per container, mounted on abulkhead near the end of each container, to accurately localize thecontainer position within that hold. This is probably beyond the numberacceptable for a cost-effective solution with current technology.Further, the incremental value of knowing the exact location of eachcontainer in the hold is probably not great, as there is no practicalway of accessing most containers once they are stacked into the hold. Inany event, the priority of finding a specific container within a hold iscertainly lower than that of accurately tracing it through loading andunloading, which has a strong economic effect (because of time) on theoverall cargo shipping and transfer process.

A solution to this problem is to deploy smart antenna structures (i.e.,multiple interconnected, horizontally polarized wire-type dipoleantennas mounted on the walls of the holds, all coupled into commoncables with remotely controlled RF PIN-diode switches). This setup wouldeffectively implement a group of scanning antenna arrays for the hold,which could identify a container being loaded into the hold and give itslocation as it is loaded. The locating function for the specific holdcan be triggered by a local container-tag RF interrogation signal (i.e.,a burst of coded RF energy at 13.56 MHz or another convenient frequency)which would be passively or semi-passively sensed by the container tagsas an “alert” or “wakeup” signal. The containers so interrogated whosecodes match the alerting signal (e.g., the last few digits of thecontainer serial ID number) would then each respond in apseudo-random-timed fashion with an HSS burst signal. The hold receivingsubsystem would acquire these signals and relay the results to the mainshipboard system for correlation with the full serial numbers in theship's container manifest database.

Another key part of the MAST system is to track the location ofcontainers at the loading dock or container yard. Given the tremendousvolume of containers moving in and out of these facilities, a trackingsystem capable of telling the facility operator where a particularcontainer is located could be a significant time-saver. Within the yard,a local spread-spectrum RF triangulation system can be used to track thecontainer location. The strategic location of four or more receiversaround the yard (more for very large facilities) would provide fordynamically tracking container locations. Additional receiving unitswould generally be located at the entries and exits of the terminal,where their data can be used to record the entry and departure ofcontainers from the facility. Typical direct line-of-sight communicationdistances in open yards should be approximately from 300 m toapproximately 500 m for tag RF transmission power levels of 10 mW,easily extending to about 1 km for 100 mW tags. Radiolocation accuraciescan be well within 1 m for typical (short) tag-read averaging times. Inaddition, greater position resolution can be obtained if longeraveraging times are utilized. A set of radiolocating receivers equippedwith adaptive beam-steering antennas would typically be installed oneach loading crane to obtain complete telemetry and location data oneach container at short range as it is being transferred to or from theship. This data set is likely to be the most reliable verification tothe tracking database system that a particular container has actuallymoved from yard to ship, or vice versa. A optional feature that can beincorporated into the container-location monitoring software is that ofmotion detection-whenever a container's position changes by more than anincidental amount (i.e., greater than the system position-uncertaintyspecification), a security routine can be activated that would thentrack the container's motion as its ID was compared against activeshipping manifests. If the container were moved a significant distance(more than normal yard unstacking/restacking operations would typicallyentail) but was not scheduled to be transferred, yard personnel wouldautomatically be alerted to a potential misplacement or theft attempt.

In general, GPS container location tracking is theoretically possiblefor containers with clear line-of-sight to the GPS satellites; but itmay not be practical in the terminal yard, particularly in stacks, forthe reasons outlined previously with regard to shipboard containers(i.e., light of sufficient line-of-sight reception). The same logicapplies to containers being transported by rail or truck.

The invention can also include optional technologies for monitoring orsensing container cargo status including a wide range of sensor devicescapable of detecting tampering with a container cargo, containertemperature, mechanical shock, radiation, stowaway, orchemical/biological agents. Some of these sensors (e.g., temperaturesensors, door switches, accelerometers, bead-type shock sensors) areessentially off-the-shelf devices that need only minor engineeringeffort to be incorporated into a container monitoring system.

Door-integrity monitoring would use a sensor to indicate if containerdoors are opened or removed. This sensor probably would be a mechanicalor magnetic switch, although other means such as optical, capacitive, orreluctance-measuring devices also could be employed. All these items areoff-the-shelf and should be easily deployed at low cost.

Radiation monitoring can be accomplished using a sensor that records theinteraction of the radiation with a material, such as a standardthermoluminescent dosimeter (TLD) of the type employed for generalemployee dosimetry monitoring. Analysis of the radiation-induced changesin the material over several days could detect even very low levels ofradiation. This sensor would not require continuous battery power, butonly battery power to intermittently measure the alteration in thesensing medium. TLDs are off-the-shelf items, and reasonably inexpensiveautomated reader units are commercially available, but the containerapplication will probably dictate a moderate optimization-engineeringeffort. To provide continuous, in-container radiation sensing, a numberof methods are available at moderate cost, depending on whether themeasurement of alpha, beta, gamma, X-ray, and/or neutron emissions isdesired, and at what sensitivity levels. For large-scale applications,the invention can include inexpensive multilayer detector materials thatcan respond to small radiation fluxes with low-level photocurrentsreadable by low-power CMOS electrometer circuitry (similar toinexpensive home smoke detectors). Radiation monitoring can also beaccomplished using the passive integrating ionizing radiation sensorsdescribed in detail below.

An alternative strategy for rapid, wide-scale radiation screening ofcontainers would probably best be implemented via a sensitivemulti-detector arrayed scanning system mounted on the loading crane orwithin the shore facility. However, because of the extreme economic timepressure in loading/unloading operations, such container scans must beconducted on the fly or else offline before (or just after) thecrane-transfer operation to avoid impacting the overall containerthroughput rate.

Monitoring for stowaways within containers can be accomplished withseveral types of sensors. The invention can include the use of aheartbeat detector, known as the Enclosed-Space Detection System. Thissensor system, including a vibration probe (e.g., accelerometer) anddetection and recognition electronics, can periodically recordmicro-vibrations in the container and analyze them via wavelet-transformmethods for the time/frequency signal signatures characteristic of human(or animal) heartbeats. This system is most effective for monitoringsingle, isolated containers (e.g., within the dock-yard) but could evenbe adapted for on-ship use. Another potential method of detectingstowaways or other unauthorized items inserted into containers would bea device to generate a specific electromagnetic field pulse inside (orinto) the container. The field levels at two or more locations wouldthen be detected, telemetered out, and recorded. Periodic re-sending ofthe electromagnetic field pulse and comparison of the new and theoriginal responses would reveal any significant changes in the fieldpatterns dictated by the distribution of material within the container.This, in turn, would indicate movement of the material within thecontainer due to either cargo shifting or the presence of humans (oranimals). Although the technology is available commercially, moreconventional (and probably less expensive) approaches to this probleminclude simpler but less-sensitive steady-state or pulsed ultrasonicand/or RF (microwave) systems similar in function to commercialintrusion alarms. The latter technologies are fundamentallyoff-the-shelf, but may be blocked or screened by cargo stacked in frontof the sensor.

Chemical/biological agents will be difficult and costly to detect,principally because extremely small amounts of these agents must besensed with high accuracy (low false negatives and false positives). Theinvention can include a chemical or biochemical “lab-on-a-chip”detector. A less expensive chem/bio detection system for containers canmount the detector on or close to the transfer crane, where thecontainer could be passed through a “sniffer tunnel” for rapid onlineexamination. In addition, individual chem./bio detector(s) can bemounted in and/or on the container(s).

Shock and/or acceleration sensing for sensitive cargoes can be realizedwith any one of several technologies, including MEMS/electronic devices(similar to automotive airbag sensors), glass beads or granules (forshock or tilt-limit sensing), piezoelectric devices (e.g., classicaccelerometers), microcantilevers and induction sensors (e.g.,geophones). The principal constraint is generally that of availablepower; most of these devices require too much power to be easily handledby a small battery for a significant time (e.g., a month). However, theuse of a continually time-sampled acceleration profile could be of greatvalue in tracking fragile cargoes and determining instances of overlyrough handling of containers in transit. Most of these types of sensorsare currently available commercially, and appropriately packaging andinterfacing them to the container telemetry system would be quick andeasy.

Refrigerated container systems, particularly the compressor and coolingsystem components, would ideally be monitored using the techniquesdiscussed previously related to the reefers. This compressor and coolingsystem technology, including the electrical-signature analysiscomponents, is readily available commercially and would bestraightforward to implement for the transportation environment.

The typical container tag-whether a simple long-range ID device or amore elaborate data-acquisition/telemetry device for detailed monitoringof container security and internal conditions (i.e., temperature,humidity, shock) is preferably battery-powered. Thus, careful unit andsystem design is also preferred to ensure proper unattended operationfor long intervals, thereby ensuring wide acceptance by the shippingindustry. The tags should preferably have periods of maintenance-freeuse of at least approximately one year. Most shipping firms would desireintervals of 3 to 5 years, approximating the lightly-loaded life of acamera-style lithium battery, which is the highest energy-density formatcurrently available in an easily obtainable commercial product. Sincethe shelf life of lithium ion batteries is typically on the order of 10years, sealed container tags stored in a deenergized state for severalyears before use should still exhibit the normal operational lifetimegoal of 3-5 years. Suggested tag query intervals in most projectedscenarios range from one to four times daily, depending on the type ofcontainer; the relative fragility or sensitivity of its cargo; and otherfactors such as security, cargo value, theft potential, and traumaticevents (e.g., a container going overboard). Some of the latter factorsmay also dictate the deployment of an emergency transmitter or beacon onthe container to facilitate immediate crew response to such urgentsituations. A routine query once per hour (expending an average of 10 mAfor 10 seconds), assuming a typical battery capacity of 1400 mAh (3-V AAsize), would result in an effective operational battery life of slightlyover 5 years. If recharging were implemented, this interval could easilyexceed 20 years, which is probably close to the expected lifetime of theelectronics package. Although solar recharging is a preferred rechargingmechanism to be employed, other power mechanisms are possible, includingmicro-fuel cells, kinetic generators (e.g., micro-pendulum or MEMStypes), thermopiles (temperature-differential), and even RF energyscavenging.

An embodiment of the invention can include embedding the RFID tag intothe structure of a container. An embodiment of the invention can includeproviding a plurality of RFID tags on a single container for redundancyor as (non)functional decoy(s).

Space Charge Dosimeters for Extremely Low Power Measurements ofRadiation in Shipping Containers

Electronic dosimeter devices can measure the dose in the container, butthey must be powered (active) during integration times. Therefore, theymust integrate over short periods to conserve battery power (thusreducing sensitivity). Utilizing large size or quantities of batteriesis not economically feasible, nor is replacing batteries during the lifeof the container (typical shipping container life is 5 to 7 years).

What is needed is a simple, rugged, low cost, low power device which canbe installed in every shipping container to passively integrateradiation dose. During transport this device could integrate theradiation dose over very long periods to obtain a very sensitivemeasurement of the presence of radiation in the container. Even wellshielded radioactive material will result in a slight increase in thebackground radiation levels in the container. What is also needed is adevice that can reduce the incidence of false positives.

Space charge dosimeters (SCD) are capable of passively integratingradiation dose continuously, while only requiring power for readout orto recharge the device. These devices work by charging or generating aninitial potential between an anode and a cathode. A dielectric media islocated between the cathode and anode. This potential creates anelectric field across the dielectric media. As radiation passes throughthe dielectric material, it causes ionization of the dielectric. Theelectric field then sweeps the ions or charge carriers out of thedielectric, thus reducing the potential between the anode and cathode.The measurement of the depleted charge during the exposure period is ameasure of integrated ionization during the measurement period. Thecharge (or some physical aspect of the device controlled by the charge)is read before and after the exposure to obtain a dose rate.

Utilizing various materials as filters around an SCD, the type ofradiation sensed can be determined or the energy range of the radiationdetermined. A suite (plurality) of these low-cost sensors in eachcontainer with a different filter around each SCD can give, not only anindication of increased background radiation, but an indication of thetype and energy levels of the radiation. This can help identify thepotential type of radioactive material in a container, e.g., identifywhether increased radiation levels in a container are due to bananas(potassium-40) rather than from cobalt-60 in a lead shielded box.

An embodiment of the invention can solve the problem of how to measureradiation in a shipping container where the radiation sensor must be lowcost and battery powered but still have a battery life of many years. Anembodiment of the invention can utilize very low cost space chargedosimeters (SCDs), such as electret ion chambers (EICs), field effecttransistors (FETs) such as IGFETs (Insulated Gate Field EffectTransistor), MOSFETs (Metal Oxide Semiconductor Field EffectTransistors) and/or micro-cantilevers, to passively integrate radiationdose. In these devices, radiation passing through the sensitive volumeof the dosimeter (the air chamber for EIC's or the dielectric layer forFETs and microcantilevers) ionizes the gas or dielectric (i.e., createscharge pairs). These radiation induced charges then lead to a change inthe potential or electric field of the device. This change in thepotential or electric field is proportional to the radiation dosereceived.

An embodiment of the invention can include an active radiation detectionvolume of material that is an electrical insulator. When radiationimpacts this volume, electric charge is created that is trapped withinthe volume. This trapped charge changes the electric field distributionwithin the volume. An embodiment of the invention can then sense thischange in field by placing electrodes on opposite sides of the volume.It is important to note that these electrodes will react to this field.If these electrodes are, for example, the gate and body of a IGFETtransistor, an embodiment of the invention can indirectly measure thechange in field by monitoring the channel conductance of the transistorwithout disturbing the trapped charge. Alternatively, if an embodimentof the invention includes a detection volume in which the generatedcharge moves toward an insulated electrode, such as, for example, amicrocantilever, the embodiment of the invention can read the cantileverdeflection and achieve the same results.

Intermittently reading the voltage or potential of the SCD dosimetergives a reading proportional to the radiation dose received by thedevice. One or more SCDs can be mounted into the shipping container,optionally in the context of a radio frequency identification tag.During transportation of the container (such as by ship or rail), theSCDs integrate received radiation dose. After a time interval, such asevery 24 hours, the voltage potential of each SCD can be read out. Thechange in potential from reading to reading is proportional to theradiation dose.

Multiple SCDs with various types of filters can be used to discriminateby types of radiation, e.g. gamma, x-ray, neutron or beta, and todiscriminate between energy levels of these particles or photons. An SCDplaced outside the container or well shielded inside the container canbe used to subtract ambient or background radiation.

The data from these radiation sensors can then be relayed to an RFID tagon the container. This RFID tag can collect the data from the radiationsensors, other sensors (for example, temperature, acoustic, etc.), andlocation information (from, for example GPS or triangulation), and sendall of it by wireless communications (e.g., HSS) to a receiver coupledto a central database. At the central database, the radiation dosereadings can be analyzed to look for indications that a container has ahigher than normal radiation field. A higher than normal radiation levelcan indicate that a hazardous (radioactive) cargo may be in thecontainer and, therefore, that a particular container needs to beflagged for more detailed inspection.

An embodiment of the invention can include a system that utilizes SpaceCharge Dosimeters (SCDs). SCDs include Electret Ion Chambers (EICs),semiconductor devices such as Insulated Gate Field Effect Transistors(IGFETs) and/or microcantilevers. The SCDs can be used to continuouslymonitor radiation levels in shipping containers. These radiation sensorscan be combined with a communications and tracking system located oneach container to allow real-time world-wide monitoring of theradiation-level in the container as well as the position of thecontainer. Unexplained or higher than expected radiation levels in acontainer can then used to flag a container for more detailed inspectionat the US port of entry, or preferably before the ship ever docks at aUS port.

As noted above, the basic principle of operation of SCDs is that theionizing radiation interacts with a material (such as air or adielectric) to create charge pairs (ionization). These charge pairs thenmigrate through the material due to the presence of an electric field.The migration and collection of the charge carriers then causes areduction in the voltage potential across the device. Once the SCD ischarged up, ionization in the active region causes a reduction in thepotential. Charging the device takes an extremely small amount of power.Once charged, the device continuously integrates the received dose,measured as a drop in the potential. Thus, reading this potential beforeand after exposure gives an indication of the received dose.Significantly, the SCD requires no power during the dose integrationperiod. The only time power is required is when charging the device orreading the potential. As also noted above, three possible SCDs that canpassively integrate dose are the Electret Ion Chamber (EIC) dosimeter,the Insulated Gate Field Effect Transistor (IGFET) dosimeter, and theMicrocantilever dosimeter.

A preferred method of operation of the radiation sensors in thisinvention is as follows. A container fitted with one or more-radiationsensors and the RFID communications system and then the container isloaded with cargo. The container is then transported to the shippingterminal. The container is then loaded onto a ship for transport to theUS or other importing country. During the ocean voyage, a signal is sentto the RFID system to activate the radiation sensor (read sensor to getbase-line reading, or recharge sensor and then get baseline reading).The radiation sensor then passively integrates received radiation doseuntil the RFID system directs the sensor for another reading or a presetamount of time has passed. The radiation sensor then powers up, readsthe voltage level, and sends the reading to the RFID system. Thisreading is then relayed to a surrounding RFID system for collection atone or more central locations and analysis. The dose integration time(intervals) can be anywhere from minutes to days. Since the ocean voyagemay last days, it is possible to allow several days of dose integrationfor extremely sensitive measurements.

A central RFID system can send a message to each container to take abaseline reading when the ship leaves port. The central system can thendirect the RFID tags to read the radiation sensors at some regularinterval (e.g., every 12 hours or 24 hours) for the duration of thevoyage. The sensor readings can be passed up to the RFID central systemby the RFID tags, tag readers, site servers, etc., whereupon thereceived doses are collected and analyzed. As the ship transits theocean (i.e. during the voyage), any radiation dose readings aboveexpected background levels will be flagged and the appropriateauthorities notified. This could permit the ship to be stopped and thecontainer inspected before the ship reaches a US port (or otherimporting country).

Electrete Ion Chamber (EIC) Dosimeters

An EIC consists of an electrically charged polymer (e.g., Teflon)filament or disk, called an electret, located inside an electricallyconductive plastic chamber having a known air volume. The electretserves as a source of high voltage (anode) needed for the chamber tooperate as an ion chamber. It also serves as a sensor for themeasurement of ionization in the chamber air. The negative ions producedinside the sensitive volume of the chamber by radiation inducedionization of the air are collected by the electret causing a depletionof charge. The measurement of the depleted charge during the exposureperiod is a measure of integrated ionization during the measurementperiod. The electret charge can be read before and after the exposure oron a known schedule using a non-contact electret voltage reader.

In a preferred embodiment of this invention, the electret charge readingvoltmeter is a very small low cost electronics circuit, or possibly anASIC chip, which not only reads the electret charge but also rechargesthe electret as needed. This circuit or chip can also contain sufficientdata to convert the measured voltage to a radiation dose and transmitthis data over a (e.g., IEEE 1451 compliant) sensor bus.

An additional optional feature of the invention is the incorporation ofradiation filtering materials or converters around EICs to make each EICsensitive to different radiation types (e.g. neutron, gamma or x-ray) orenergies (hard x-ray, soft x-ray, etc). Measuring not only the presenceor quantity of increased radiation levels but also some qualitativecharacteristics of the radiation can help distinguish hazardousradioactive cargo from normal safe cargo having a normally higherradiation level (such as bananas, some pottery, etc). Additionally, oneEIC sensor can be mounted and shielded to measure background radiationfor background subtraction from the sensor measurements inside thecontainer.

EIC devices are shock sensitive and can be partially discharged whenshaken or dropped. To prevent false positive radiation measurements dueto the severe handling experienced by shipping containers, the inventioncan incorporate active and passive preventative measures. First, theability to communicate to each sensor via the RFID tag on each containerpermits the radiation sensors to integrate does and then be readoutduring times of known low shock potential, such as during marinetransport. Readings can be taken starting when the ship leaves port andduring the duration of the voyage. Second, an accelerometer can beco-located with the sensors to identify shock events of sufficientmagnitude to cause discharge of the EIC. After such events, the EIC canbe readout and the dose integration time re-initiated.

Field Effect Transistor Dosimeters

FET dosimeter operation is based on the generation of electron-holepairs in the oxide (or other insulator material having very low holemobility) of the (e.g., IGFET) structure (gate oxide) due to theionizing radiation. The energy to produce one electron-hole (e-h) pairin silicon oxide is about 18 eV. The electron mobility is such thatelectrons collect on the gate of the transistor (assuming an n-channeldevice) but the hole mobility is much smaller. The holes are thereforeeffectively immobilized within the oxide between the gate and body. Thiscauses a variation in the electric field between the gate and thechannel of the transistor which changes the current-carryingcapabilities of the channel. This change can then be read at any timewithout affecting the dosimetrically-altered electric field. Therefore,the gate bias voltage is a direct measure of the absorbed radiationdose. This technique can be applied to both FETs intentionallymanufactured in a given CMOS process or to field-oxide FETs (parasiticFETs, IGFETs). The latter of which will exhibit more sensitivity due tothicker oxides.

Microcantilever Dosimeters

Microcantilever dosimeters are created by making the microcantilever anelectrode separated from ground by an insulator. A charge is applied tothe microcantilever. This charge remains unchanged until radiationcreates electron-hole pairs in the insulator. Thus, absorbed radiationdose is continuously and passively integrated. To read-out the radiationdose, the change in the voltage potential on the microcantilever ismeasured. This potential or change in potential is determined bymeasuring the deflection of the microcantilever.

Filters and Converters for Discriminating between Types of Radiation orEnergy Levels

The invention can include the use of different types and thicknesses ofmaterials to make radiation sensors sensitive to particular types ofradiation or to different energy levels. The invention can include theuse of a plurality (e.g., an array) of low-cost detectors, each with adifferent filter, in the shipping container. Since the types of SCDradiation detectors described above can be mass produced at a very lowcost, an array of detectors can be located throughout a container.Filters of varying density metals such as lead, tin, and aluminum can beused to coarsely determine the energy of impinging gamma or x-rays. Aradiation converter such as boron or lithium-6 can be used to make thedevices sensitive to thermal neutrons. Teflon or a high hydrogen contentplastic can be used to increase sensitivity to intermediate energyneutrons. By using an array of detectors, each utilizing a differentfilter and converter, located inside the container, any radiationdetected in the container can be categorized into energy bands (forexample, low, mid, and high) and radiation type (beta, x-ray, gamma).

RFID Communications System

The invention can combine the radiation sensors with a communicationsand tracking system that relays the sensor data and container locationto a centralized database where the radiation data from every containercan be analyzed to flag containers requiring further detailedinspection. The overall RFID system can be termed a “Marine AssetSecurity and Tracking (MAST) System.” The MAST System is preferably awireless (RF)-based communications and sensing/telemetry system fortracking and monitoring maritime industry-standard shipping containers,both during loading, unloading, and transfer operations at portside dockfacilities, as well as onboard ships during overseas transport of thecontainers. This system also provides a true inter-modal tracking andmonitoring system capable of operating on ships, railroads,over-the-road trucks and within their associated terminal facilities,utilizing both local-terminal communications systems and other wide-areacommercial communications systems, including satellite and/orcellular/PCS. This RFID tagging system can include RFID tags attached toeach shipping container, local site readers located throughout the shipand in the shipping terminal, one central site server on each ship or ineach terminal, and a National Operations Center (NOC) where all data iscollected, consolidated, stored, analyzed and disseminated. The shippingcontainers can be both refrigerated-cargo shipping containers (reefers)and dry-cargo shipping containers (dry-boxes). In addition toidentifying and tracking the location of containers or other equipmentfitted with one of the RFID tags, each tag is equipped with, forexample, an IEEE 1451 sensor interface and extra serial interfaces topermit the connection of a wide range of sensors to the RFID tag tomonitor the condition of the container cargo or other tagged equipment.Other sensors which can be connected to the RFID tag include (but arenot limited to) temperature, pressure, relative humidity, accelerometer,radiation, door seals, and GPS (Global Positioning System). Additionalsensors can also be included for condition monitoring of machinery, suchas refrigeration compressors, or to read the diagnostic data port onsome refrigerated cargo containers.

This invention can include implementation of a radiation sensor systemfor the MAST system RFID tags. The MAST system provides the solution tothe problem of combining the data from a container installation with anoverall monitoring, tracking or communications system, while the problemof not using power during the dose integration time is addressed byusing a suite of passively-integrating radiation sensors. An embodimentof the invention can include a class of radiation dosimeters thatcontinuously, passively integrate radiation dose, send this data to theRFID tag on the container via a IEEE 1451 sensor interface, and thentransmits this data with position and other sensor data to the MASTsystem National Operations Center (NOC). At the NOC, all sensor data,container manifest, route traveled by the container and otherinformation is analyzed and used to identify containers for detailedinspection at Ports of Entry.

The invention can include passively integrating radiation dose over longperiods, while only using power to read out the received dose. Theinvention can include connecting a radiation sensor to a RFID systemwhich will communicate out the sensor data in near-real time to acentral database where analysis of the sensor data can be performed toidentify and flag containers with abnormal radiation readings.

The invention can include insitu polling a suite of passive integratingionizing radiation sensors including reading-out dosimetric data from afirst passive integrating ionizing radiation sensor and a second passiveintegrating ionizing radiation sensor, wherein the first passiveintegrating ionizing radiation sensor and the second passive integratingionizing radiation sensor remain situated where the dosimetric data wasintegrated while reading-out dosimetric data and wherein the firstpassive integrating radiation sensor and the second integratingradiation sensor are connected to read-out circuits presenting extremelyhigh impedance while in a passive integration mode and while in anactive read-out mode, without destruction of integrated dosimetric dataallowing continuous integration of ionizing radiation to a maximumextent of the first passive integrating ionizing radiation sensor andthe second passive integrating ionizing radiation sensor. Upon sensingthe attainment of maximum integration limits, readout circuits can resetpassive integrating radiation sensors and accumulate in a non-volatilemanner the number of sensor reset cycles.

The invention can include a first passive integrating ionizing radiationsensor; a second passive integrating ionizing radiation sensor; aread-out circuit coupled to both the first passive integrating ionizingradiation sensor and the second passive integrating ionizing radiationsensor, the read-out circuit presenting an extremely high impedance toboth the first passive integrating ionizing radiation sensor and thesecond passive integrating ionizing radiation sensor both while theread-out circuit is in a passive integration mode and while the read-outcircuit is in an active read-out mode; and a communication circuitcoupled to the read-out circuit, wherein read-out dosimetric data fromboth the first passive integrating radiation sensor and the secondpassive integrating radiation sensor is presented to the communicationscircuit.

One or both of the first passive integrating ionizing radiation sensorand the second passive integrating ionizing radiation sensor can includea thick oxide insulated gate field effect transistor space chargedosimeter. The read-out circuits can present impedance of fromapproximately 10¹¹ ohms to approximately 10¹⁵ ohms, preferably fromapproximately 10¹² ohms to approximately 10¹⁴ ohms, most preferablyapproximately 10¹³ ohms.

As noted above, the invention can include a thick oxide dosimeter (TOD).In such a TOD, the FETs can be arranged such that the gates areconnected to two or more levels of metal or polysilicon. This willincrease the active volume of SiO₂ that can interact with ionizingradiation. These devices have the significant optional advantage oftemperature and process compensation by reading out the voltage betweenthe drains assuming the sources are connected to a common electricalpotential. The gates and drains for a given IGFET can be connectedtogether.

This technique can be extended by simply adding FETS and stacking metallayers on top of each other to the limits of the semiconductorfabrication process being used. The advantage of this is that the activevolume of the oxide used for detection is increased but the electricfield created by a trapped charge between any two plates is reduced bythe increase in distance between the plates. As many plates as thefabrication process allows can be used to obtain the greatest electricfield for a given ionizing radiation event to ensure the greatestprobability of detection.

FIGS. 10-11 depict two IGFET examples of the invention. The use of theterms first, second and third in describing elements depicted in thesefigures is only for distinguishing between similar elements and theassignment of these terms is arbitrary.

Referring to FIG. 10, a suite of passive integrating ionizing radiationsensors includes a first sensor 1010 shielded by a first filter 1011.This suite of passive integrating ionizing radiation sensors alsoincludes a second sensor 1020 shielded by a second filter 1021. Thefirst sensor 1010 and the second sensor 1020 are both coupled to acommunications circuit 1030. A temperature compensation circuit 1040 iscoupled to the communications circuit 1030. A calibration circuit 1050is also coupled to the communications circuit 1030. Each of the sensors1010, 1020 is based on a pair of insulated gate field effecttransistors.

The invention can include an apparatus, comprising: a thick oxidedosimeter; and a readout circuit coupled to the thick oxide dosimeter,wherein both the thick oxide dosimeter and the readout circuit areconstructed on a single high impedance and low leakage substrate. Thethick oxide dosimeter can include a thick oxide insulated gate fieldeffect transistor space charge dosimeter. The single high impedance andlow leakage substrate can include a construction of silicon on sapphire,silicon on insulator and/or transmutated high resistivity silicon. Thesubstrate can have an impedance of from approximately 10¹¹ ohms toapproximately 10¹⁵ ohms, preferably from approximately 10¹² ohms toapproximately 10¹⁴ ohms, most preferably approximately 10¹³ ohms.

Referring to FIG. 11, a passive integrating ionizing radiation sensor1100 includes a first active area (region) 1110 and a second active area(region) 1120. The second active area 1110 is sandwiched between acommon conductor 1130 and a first active area conductor 1140. The secondactive area 11 20 is sandwiched between the common conductor 1130 and asecond active area conductor 1150. The first active area conductor 1140is coupled to the gate of a first insulated gate field effect transistor1160. The second active area conductor 1150 is coupled to the gate of asecond insulated gate field effect transistor 1170. The sources of boththe first insulated gate field effect transistor 1160 and the secondinsulated gate field effect transistor 1170 are connected together andcoupled to the common conductor 1130. A third insulated gate fieldeffect transistor 1180 provides an integrated temperature compensationfunctionality.

During passive-mode dosimetry operation of the examples depicted in FIG.11, ionizing radiation passes through the active area and generates anet charge that is trapped in the oxide. This charge generates anelectric field between the adjacent conductors thus creating a netchange in the resistance seen between the source and gate of the FETwhose active area was hit. During readout operation of the examplesdepicted in FIG. 11, the resistance between the source and each drain isread. The net amount of radiation is proportional to the change inresistance. Temperature compensation is applied by tracking the changein the third IGFET which has a much smaller radiation sensitivity thanthe others.

The invention can include a first insulated gate field effect transistorincluding a first source, a first drain and a first insulated gate; asecond insulated gate field effect transistor including a second source,a second drain and a second insulated gate, the second source coupled tothe first source; a first conductor coupled to the second gate; a firstactive region connected to the first conductor, the first active regionaccumulating dosimetric data from incident ionizing radiation; a secondconductor connected to the first active region; a second active regioncoupled to the second conductor, the second active region accumulatingdosimetric data from incident ionizing radiation; and a third conductorcoupled between the second active region and the first gate, wherein thesecond conductor is coupled to both the first source and the secondsource. A third insulated gate field effect transistor can providetemperature compensation data.

The invention can include arranging a plurality of sensors in aspatially dispersed (e.g., an array) configuration and setting an alarmcondition based on a reading in multiple sensors.

The invention can include pattern recognition. For example, a method caninclude arranging a plurality of passive integrating ionizing radiationsensors in a spatially dispersed array; determining a relative positionof each of the plurality of passive integrating ionizing radiationsensors to define a volume of interest; collecting ionizing radiationdata from at least a subset of the plurality of passive integratingionizing radiation sensors; and triggering an alarm condition whencollected ionizing radiation data from the subset of the plurality ofpassive integrating ionizing radiation sensors meets a predeterminedspatial pattern criterion. The predetermined spatial pattern criterioncan include a plurality of alternative patterns. The predeterminedspatial pattern criterion can include a dosimetric data pattern definedby a function that includes a cube root of a radius from an approximatelocation of an ionizing radiation source.

Embodiments of the invention, can be cost effective and advantageous forat least the following reasons. An embodiment of the invention canprovide world-wide asset and/or cargo tracking, monitoring and security.An embodiment of the invention can include Integrating RFID tag data ina GIS-based system for asset tracking, management, and visualization. Anembodiment of the invention can include RFID tag communicationsutilizing hybrid spread-spectrum signaling. An embodiment of theinvention can include multi-access technology allowing communicationswith over 10,000 RFID tags, while ignoring up to 90,000 tags, in thesame RFID tag reader zone. Embodiments of the invention improves qualityand/or reduces costs compared to previous approaches.

The phrase hybrid spread-spectrum (HSS) as used herein is defined as acombination of direct sequence spread-spectrum (DSSS), for example codedivision multiple access (CDMA), and at least one of frequency hopping,time hopping, time division multiple access (TDMA), orthogonal frequencydivision multiplexing OFDM and/or spatial division multiple access(SDMA). The terms a or an, as used herein, are defined as one or morethan one. The term plurality, as used herein, is defined as two or morethan two. The term another, as used herein, is defined as at least asecond or more. The terms “comprising” (comprises, comprised),“including” (includes, included) and/or “having” (has, had), as usedherein, are defined as open language (i.e., requiring what is thereafterrecited, but open for the inclusion of unspecified procedure(s),structure(s) and/or ingredient(s) even in major amounts. The terms“consisting” (consists, consisted) and/or “composing” (composes,composed), as used herein, close the recited method, apparatus orcomposition to the inclusion of procedures, structure(s) and/oringredient(s) other than those recited except for ancillaries, adjunctsand/or impurities ordinarily associated therewith. The recital of theterm “essentially” along with the terms “consisting” or “composing”renders the recited method, apparatus and/or composition open only forthe inclusion of unspecified procedure(s), structure(s) and/oringredient(s) which do not materially affect the basic novelcharacteristics of the composition. The term coupled, as used herein, isdefined as connected, although not necessarily directly, and notnecessarily mechanically. The term any, as used herein, is defined asall applicable members of a set or at least a subset of all applicablemembers of the set. The term approximately, as used herein, is definedas at least close to a given value (e.g., preferably within 10% of, morepreferably within 1% of, and most preferably within 0.1% of). The termsubstantially, as used herein, is defined as largely but not necessarilywholly that which is specified. The term generally, as used herein, isdefined as at least approaching a given state. The term deploying, asused herein, is defined as designing, building, shipping, installingand/or operating. The term means, as used herein, is defined ashardware, firmware and/or software for achieving a result. The termprogram or phrase computer program, as used herein, is defined as asequence of instructions designed for execution on a computer system. Aprogram, or computer program, may include a subroutine, a function, aprocedure, an object method, an object implementation, an executableapplication, an applet, a servlet, a source code, an object code, ashared library/dynamic load library and/or other sequence ofinstructions designed for execution on a computer or computer system.The term proximate, as used herein, is defined as close, near adjacentand/or coincident; and includes spatial situations where the specifiedfunctions and/or results can be carried out and/or achieved. The phraseradio frequency, as used herein, is defined as including infrared, aswell as frequencies less than or equal to approximately 300 GHz.

All the disclosed embodiments of the invention disclosed herein can bemade and used without undue experimentation in light of the disclosure.An embodiment of the invention is not limited by theoretical statementsrecited herein. Although the best mode of carrying out embodiments ofthe invention contemplated by the inventor(s) is disclosed, practice ofan embodiment of the invention is not limited thereto. Accordingly, itwill be appreciated by those skilled in the art that an embodiment ofthe invention may be practiced otherwise than as specifically describedherein.

It will be manifest that various substitutions, modifications, additionsand/or rearrangements of the features of an embodiment of the inventionmay be made without deviating from the spirit and/or scope of theunderlying inventive concept. It is deemed that the spirit and/or scopeof the underlying inventive concept as defined by the appended claimsand their equivalents cover all such substitutions, modifications,additions and/or rearrangements.

All the disclosed elements and features of each disclosed embodiment canbe combined with, or substituted for, the disclosed elements andfeatures of every other disclosed embodiment except where such elementsor features are mutually exclusive. Variation may be made in the stepsor in the sequence of steps defining methods described herein.

Although the sensor(s) with or without their filters described hereincan be a separate module, it will be manifest that the sensor(s) may beintegrated into the system with which it is (they are) associated. Theindividual components need not be formed in the disclosed shapes, orcombined in the disclosed configurations, but could be provided in allshapes, and/or combined in all configurations. The individual componentsneed not be fabricated from the disclosed materials, but could befabricated from all suitable materials.

The appended claims are not to be interpreted as includingmeans-plus-function limitations, unless such a limitation is explicitlyrecited in a given claim using the phrase(s) “means for” and/or “stepfor.” Subgeneric embodiments of the invention are delineated by theappended independent claims and their equivalents. Specific embodimentsof the invention are differentiated by the appended dependent claims andtheir equivalents.

1. A method, comprising transmitting identification data, location dataand environmental state sensor data from a radio frequency tag.
 2. Themethod of claim 1, further comprising depicting a location of the radiofrequency tag using a geographic information system.
 3. The method ofclaim 1, wherein the radio frequency tag adjusts, with regard to theenvironmental state sensor data, a set point to lower power consumption.4. The method of claim 1, wherein the radio frequency tag can beswitched to a transceiver mode that permits tag to tag communication. 5.The method of claim 4, wherein transceiver mode includes the radiofrequency tag transmitting during a randomized transmission interval andthen receiving and buffering.
 6. The method of claim 4, wherein theradio frequency tag is switched to the transceiver mode when an alarmstate is activated.
 7. The method of claim 1, wherein the radiofrequency tag includes a power source including an energy storage devicethat is recharged by at least one current source selected from the groupconsisting of a photovoltaic, a vibrational transducer, an electrostaticcharger, a radio frequency power rectifier, a thermoelectric generatorand a radioisotope decay energy recovery device.
 8. The method of claim1, further comprising receiving identification data, location data andenvironmental state sensor data from the radio frequency tag at areader.
 9. The method of claim 8, wherein the radio frequency tag can beswitched to a transceiver mode that permits tag to tag communication.10. The method of claim 9, wherein transceiver mode includes the radiofrequency tag transmitting during a randomized transmission interval andthen receiving and buffering.
 11. The method of claim 9, wherein theradio frequency tag is switched to a tag to tag mode when the radiofrequency tag does not receive a response from the reader
 12. The methodof claim 9, wherein the radio frequency tag is switched to thetransceiver mode when an alarm state is activated.
 13. The method ofclaim 8, further comprising depicting a location of the radio frequencytag using a geographic information system.
 14. The method of claim 1,wherein the radio frequency tag includes a sensor.
 15. The method ofclaim 14, wherein the sensor characterizes at least one member selectedfrom the group consisting of ionizing radiation, chemical moieties,biological species, acoustic emission, mechanical vibration and actinicradiation.
 16. The method of claim 14, wherein the sensor characterizesat least one member selected from the group consisting ofelectromagnetic radiation, humidity, temperature, vibration,acceleration and mechanical interlock.
 17. The method of claim 16,wherein the radio frequency tag adjusts, with regard to the sensor, aset point to lower power consumption.
 18. The method of claim 1, furthercomprising a sensor coupled to the radio frequency tag.
 19. The methodof claim 18, wherein the sensor characterizes at least one memberselected from the group consisting of ionizing radiation, chemicalmoieties, biological species, acoustic emission, mechanical vibrationand actinic radiation.
 20. The method of claim 18, wherein the sensorcharacterizes at least one member selected from the group consisting ofelectromagnetic radiation, humidity, temperature, vibration,acceleration and mechanical interlock.
 21. The method of claim 18,wherein the radio frequency tag adjusts, with regard to the sensor, aset point to lower power consumption.
 22. The method of claim 18,wherein the sensor includes a power source that is not necessary for thetag to transmit identification data and location data.
 23. The apparatusof claim 22, wherein the power source includes an energy storage devicethat is recharged by at least one current source selected from the groupconsisting of a photovoltaic, a vibrational transducer, an electrostaticcharger, a radio frequency power rectifier, a thermoelectric generatorand a radioisotope decay energy recovery device.
 24. The method of claim18, wherein the sensor is coupled to the radio frequency tag wirelesslyby at least one member selected from the group consisting of hybridspread-spectrum, direct sequence spread-spectrum, frequency hopping,time hopping, time division multiplexing, orthogonal frequency divisionmultiplexing and infrared.
 25. The method of claim 24, whereinidentification data, location data and environmental state sensor datafrom the radio frequency tag is transmitted within a first frequencyband and the sensor is coupled to the radio frequency tag wirelesslywithin a second frequency band that does not overlap the first frequencyband.
 26. The method of claim 1, further comprising receivingidentification data, location data and environmental state sensor datafrom the radio frequency tag at a reader and re-transmittingidentification data, location data and environmental state sensor datafrom the reader to a site server that provides data accumulation andanalysis.
 27. The method of claim 26, further comprising depicting alocation of the radio frequency tag using a geographic informationsystem.
 28. The method of claim 26 wherein transmitting identificationdata, location data and environmental state sensor data from the radiofrequency tag occurs within a first frequency band and re-transmittingidentification data, location data and environmental state sensor datafrom the reader to the site server occurs within a second frequency bandthat does not overlap the first frequency band.
 29. The method of claim26, wherein re-transmitting identification data, location data andenvironmental state sensor data from the reader to the site server caninclude wireless transmission by at least two alternatives selected fromthe group consisting of hybrid spread-spectrum, direct sequencespread-spectrum, frequency hopping, time hopping, time divisionmultiplexing, orthogonal frequency division multiplexing and infrared.30. The method of claim 26, wherein re-transmitting identification data,location data and environmental state sensor data from the reader to thesite server includes transmission on a reader power supply line
 31. Themethod of claim 30, wherein re-transmitting identification data,location data and environmental state sensor data from the reader to thesite server includes transmission by at least one member selected fromthe group consisting of hybrid spread-spectrum, direct sequencespread-spectrum, frequency hopping, time hopping, time divisionmultiplexing, orthogonal frequency division multiplexing and infrared.32. The method of claim 30, wherein re-transmitting identification data,location data and environmental state sensor data from the reader to thesite server includes rejecting noise at a frequency selected from thegroup consisting of approximately 50 Hz and approximately 60 Hz andsubstantially all harmonics thereof and diversifying.
 33. The method ofclaim 26, wherein re-transmitting identification data, location data andenvironmental state sensor data from the reader to the site serverincludes wireless transmission by at least one member selected from thegroup consisting of hybrid spread-spectrum, direct sequencespread-spectrum, frequency hopping, time hopping, time divisionmultiplexing, orthogonal frequency division multiplexing and infrared.34. The method of claim 33, wherein wireless transmission by hybridspread-spectrum modulation includes rejecting noise at a frequencyselected from the group consisting of approximately 50 Hz andapproximately 60 Hz and substantially all harmonics thereof anddiversifying.
 35. The method of claim 26, further comprising receivingidentification data, location data and environmental state sensor datafrom the reader at the site server and re-transmitting identificationdata, location data and environmental state sensor data from the siteserver to at least one server of a common database that providesanalysis, comparison and tracking.
 36. The method of claim 35, furthercomprising depicting a location of the radio frequency tag using ageographic information system.
 37. The method of claim 35, wherein thecommon database defines a global database.
 38. The method of claim 35,wherein re-transmitting identification data, location data andenvironmental state sensor data from the site server to the commondatabase can include transmission by at least two alternatives selectedfrom the group consisting of satellite, cellphone, acoustic, power line,telephone line, coaxial line, optical fiber and optical cable.
 39. Themethod of claim 35, wherein re-transmitting identification data,location data and environmental state sensor data from the site serverto the common database includes transmission by internet.
 40. Anapparatus, comprising: a radio frequency tag that transmitsidentification data, location data and environmental state sensor data.41. The apparatus of claim 40, wherein the radio frequency tag includesa power source including an energy storage device that is recharged byat least one current source selected from the group consisting of aphotovoltaic, a vibrational transducer, an electrostatic charger, aradio frequency power rectifier, a thermoelectric generator and aradioisotope decay energy recovery device.
 42. The apparatus of claim40, wherein the radio frequency tag includes a sensor.
 43. The apparatusof claim 42, wherein the sensor characterizes at least one memberselected from the group consisting of ionizing radiation, chemicalmoieties, biological species, acoustic emission, mechanical vibrationand actinic radiation.
 44. The apparatus of claim 42, wherein the sensorcharacterizes at least one member selected from the group consisting ofelectromagnetic radiation, humidity, temperature, vibration,acceleration and mechanical interlock.
 45. The apparatus of claim 40,further comprising a sensor coupled to the radio frequency tag.
 46. Theapparatus of claim 45, wherein the sensor characterizes at least onemember selected from the group consisting of ionizing radiation,chemical moieties, biological species, acoustic emission, mechanicalvibration and actinic radiation.
 47. The apparatus of claim 45, whereinthe sensor characterizes at least one member selected from the groupconsisting of electromagnetic radiation, humidity, temperature,vibration, acceleration and mechanical interlock.
 48. The apparatus ofclaim 45, wherein the sensor includes a power source that is notnecessary for the tag to transmit identification data, location data andenvironmental state data.
 49. The apparatus of claim 48, wherein thepower source includes an energy storage device that is recharged by atleast one current source selected from the group consisting of aphotovoltaic, a vibrational transducer, an electrostatic charger, aradio frequency power rectifier, a thermoelectric generator and aradioisotope decay energy recovery device.
 50. The apparatus of claim45, wherein the sensor is coupled to the radio frequency tag wirelesslyby at least one member selected from the group consisting of hybridspread-spectrum, direct sequence spread-spectrum, frequency hopping,time hopping, time division multiplexing, orthogonal frequency divisionmultiplexing and infrared.
 51. The apparatus of claim 50, whereinidentification data, location data and environmental state sensor datafrom the radio frequency tag is transmitted within a first frequencyband and the sensor is coupled to the radio frequency tag wirelesslywithin a second frequency band that does not overlap the first frequencyband.
 52. The apparatus of claim 40, wherein the radio frequency tag iscoupled to a shipping container.
 53. The apparatus of claim 52, whereinenvironmental state sensor data includes an environmental state insidethe shipping container.
 54. The apparatus of claim 52, furthercomprising an antenna coupled to the shipping container.
 55. Theapparatus of claim 52, wherein the shipping container includes ashipping container power supply and the radio frequency tag can tap intothe shipping container power supply.
 56. The apparatus of claim 55,wherein the shipping container includes one member selected from thegroup consisting of a dry box and a reefer.
 57. The apparatus of claim40, further comprising a reader wirelessly coupled to the radiofrequency tag, the reader receiving identification data, location dataand environmental state sensor data from the radio frequency tag andre-transmitting identification data, location data and environmentalstate sensor data from the reader to a site server that provides dataaccumulation and analysis.
 58. The apparatus of claim 57, whereintransmitting identification data, location data and environmental statesensor data from the radio frequency tag occurs within a first frequencyband and re-transmitting identification data, location data andenvironmental state sensor data from the reader to the site serveroccurs within a second frequency band that does not overlap the firstfrequency band.
 59. The apparatus of claim 58, wherein re-transmittingidentification data, location data and environmental state sensor datafrom the reader to the site server can include wireless transmission byat least two alternatives selected from the group consisting of hybridspread-spectrum, direct sequence spread-spectrum, frequency hopping,time hopping, time division multiplexing, orthogonal frequency divisionmultiplexing and infrared.
 60. The apparatus of claim 57, wherein thereader is electrically coupled to the site server via a reader powersupply line and re-transmitting identification data, location data andenvironmental state sensor data from the reader to the site serverincludes transmission on the reader power supply line
 61. The apparatusof claim 60, wherein re-transmitting identification data, location dataand environmental state sensor data from the reader to the site serverincludes transmission by at least one member selected from the groupconsisting of hybrid spread-spectrum, direct sequence spread-spectrum,frequency hopping, time hopping, time division multiplexing, orthogonalfrequency division multiplexing and infrared.
 62. The apparatus of claim60, wherein re-transmitting identification data, location data andenvironmental state sensor data from the reader to the site serverincludes rejecting noise at a frequency selected from the groupconsisting of approximately 50 Hz and approximately 60 Hz andsubstantially all harmonics thereof and diversifying.
 63. The apparatusof claim 57, wherein re-transmitting identification data, location dataand environmental state sensor data from the reader to the site serverincludes wireless transmission by at least one member selected from thegroup consisting of hybrid spread-spectrum, direct sequencespread-spectrum, frequency hopping, time hopping, time divisionmultiplexing, orthogonal frequency division multiplexing and infrared.64. The apparatus of claim 63, wherein wireless transmission by hybridspread-spectrum modulation includes rejecting noise at a frequencyselected from the group consisting of approximately 50 Hz andapproximately 60 Hz and substantially all harmonics thereof anddiversifying.
 65. The apparatus of claim 57, further comprising a siteserver wirelessly coupled to the reader, the site server receivingidentification data, location data and environmental state sensor datafrom the reader and re-transmitting identification data, location dataand environmental state sensor data from the site server to at least oneserver of a common database that provides analysis, comparison andtracking.
 66. The apparatus of claim 65, wherein the common databasedefines a global database.
 67. The apparatus of claim 65, whereinre-transmitting identification data, location data and environmentalstate sensor data from the site server to the common database caninclude transmission by at least two alternatives selected from thegroup consisting of satellite, cellphone, acoustic, power line,telephone line, coaxial line, optical fiber and optical cable.
 68. Theapparatus of claim 65, wherein re-transmitting identification data,location data and environmental state sensor data from the site serverto the common database includes transmission by internet.
 69. A vehicle,comprising the apparatus of claim
 40. 70. A port area network,comprising the apparatus of claim
 40. 71. A regional area network,comprising the apparatus of claim
 40. 72. A national area network,comprising the apparatus of claim
 40. 73. A global area network,comprising the apparatus of claim
 40. 74. A method, comprisingtransmitting identification data and location data from a radiofrequency tag using hybrid spread-spectrum modulation.
 75. The method ofclaim 74, further comprising depicting a location of the radio frequencytag using a geographic information system.
 76. The method of claim 74,further comprising transmitting environmental state sensor data from theradio frequency tag using hybrid spread-spectrum modulation.
 77. Themethod of claim 76, wherein the radio frequency tag adjusts, with regardto the environmental state sensor data, a set point to lower powerconsumption.
 78. The method of claim 74, wherein the radio frequency tagcan be switched to a transceiver mode that permits tag to tagcommunication.
 79. The method of claim 78, wherein transceiver modeincludes the radio frequency tag transmitting during a randomizedtransmission interval and then receiving and buffering.
 80. The methodof claim 78, wherein the radio frequency tag is switched to thetransceiver mode when an alarm state is activated.
 81. The method ofclaim 80, wherein the radio frequency tag includes a power sourceincluding an energy storage device that is recharged by at least onecurrent source selected from the group consisting of a photovoltaic, avibrational transducer, an electrostatic charger, a radio frequencypower rectifier, a thermoelectric generator and a radioisotope decayenergy recovery device.
 82. The method of claim 74, further comprisingreceiving identification data and location data from the radio frequencytag at a reader.
 83. The method of claim 82, wherein the radio frequencytag can be switched to a transceiver mode that permits tag to tagcommunication.
 84. The method of claim 83, wherein transceiver modeincludes the radio frequency tag transmitting during a randomizedtransmission interval and then receiving and buffering.
 85. The methodof claim 83, wherein the radio frequency tag is switched to a tag to tagmode when the radio frequency tag does not receive a response from thereader
 86. The method of claim 83, wherein the radio frequency tag isswitched to the transceiver mode when an alarm state is activated. 87.The method of claim 74, further comprising depicting a location of theradio frequency tag using a geographic information system.
 88. Themethod of claim 74, wherein the radio frequency tag includes a sensor.89. The method of claim 88, wherein the sensor characterizes at leastone member selected from the group consisting of ionizing radiation,chemical moieties, biological species, acoustic emission, mechanicalvibration and actinic radiation.
 90. The method of claim 88, wherein thesensor characterizes at least one member selected from the groupconsisting of electromagnetic radiation, humidity, temperature,vibration, acceleration and mechanical interlock.
 91. The method ofclaim 90, wherein the radio frequency tag adjusts, with regard to thesensor, a set point to lower power consumption.
 92. The method of claim74, further comprising a sensor coupled to the radio frequency tag. 93.The method of claim 92, wherein the sensor characterizes at least onemember selected from the group consisting of ionizing radiation,chemical moieties, biological species, acoustic emission, mechanicalvibration and actinic radiation.
 94. The method of claim 92, wherein thesensor characterizes at least one member selected from the groupconsisting of electromagnetic radiation, humidity, temperature,vibration, acceleration and mechanical interlock.
 95. The method ofclaim 92, wherein the radio frequency tag adjusts, with regard to thesensor, a set point to lower power consumption.
 96. The method of claim92, wherein the sensor includes a power source that is not necessary forthe tag to transmit identification data and location data.
 97. Themethod of claim 96, wherein the power source includes an energy storagedevice that is recharged by at least one current source selected fromthe group consisting of a photovoltaic, a vibrational transducer, anelectrostatic charger, a radio frequency power rectifier, athermoelectric generator and a radioisotope decay energy recoverydevice.
 98. The method of claim 92, wherein the sensor is coupled to theradio frequency tag wirelessly by at least one member selected from thegroup consisting of hybrid spread-spectrum, direct sequencespread-spectrum, frequency hopping, time hopping, time divisionmultiplexing, orthogonal frequency division multiplexing and infrared.99. The method of claim 98, wherein identification data and locationdata from the radio frequency tag is transmitted within a firstfrequency band and the sensor is coupled to the radio frequency tagwirelessly within a second frequency band that does not overlap thefirst frequency band.
 100. The method of claim 74, further comprisingreceiving identification data and location data from the radio frequencytag at a reader and re-transmitting identification data and locationdata from the reader to a site server that provides data accumulationand analysis.
 101. The method of claim 100, further comprising depictinga location of the radio frequency tag using a geographic informationsystem.
 102. The method of claim 100 wherein transmitting identificationdata and location data from the radio frequency tag occurs within afirst frequency band and re-transmitting identification data andlocation data from the reader to the site server occurs within a secondfrequency band that does not overlap the first frequency band.
 103. Themethod of claim 100, wherein re-transmitting identification data andlocation data from the reader to the site server can include wirelesstransmission by at least two alternatives selected from the groupconsisting of hybrid spread-spectrum, direct sequence spread-spectrum,frequency hopping, time hopping, time division multiplexing, orthogonalfrequency division multiplexing and infrared.
 104. The method of claim100, wherein re-transmitting identification data and location data fromthe reader to the site server includes transmission on a reader powersupply line
 105. The method of claim 104, wherein re-transmittingidentification data and location data from the reader to the site serverincludes by transmission at least one member selected from the groupconsisting of hybrid spread-spectrum, direct sequence spread-spectrum,frequency hopping, time hopping, time division multiplexing, orthogonalfrequency division multiplexing and infrared.
 106. The method of claim104, wherein re-transmitting identification data and, location data fromthe reader to the site server includes rejecting noise at a frequencyselected from the group consisting of approximately 50 Hz andapproximately 60 Hz and substantially all harmonics thereof anddiversifying.
 107. The method of claim 100, wherein re-transmittingidentification data, location data and environmental state sensor datafrom the reader to the site server includes wireless transmission by atleast one member selected from the group consisting of hybridspread-spectrum, direct sequence spread-spectrum, frequency hopping,time hopping, time division multiplexing, orthogonal frequency divisionmultiplexing and infrared.
 108. The method of claim 107, whereinwireless transmission by hybrid spread-spectrum modulation includesrejecting noise at a frequency selected from the group consisting ofapproximately 50 Hz and approximately 60 Hz and substantially allharmonics thereof and diversifying.
 109. The method of claim 100,further comprising receiving identification data and location data fromthe reader at the site server and re-transmitting identification dataand location data from the site server to at least one server of acommon database that provides analysis, comparison and tracking. 110.The method of claim 109, further comprising depicting a location of theradio frequency tag using a geographic information system.
 111. Themethod of claim 109, wherein the common database defines a globaldatabase.
 112. The method of claim 109, wherein re-transmittingidentification data and location data from the site server to the commondatabase can include transmission by at least two alternatives selectedfrom the group consisting of satellite, cellphone, acoustic, power line,telephone line, coaxial line, optical fiber and optical cable.
 113. Themethod of claim 109, wherein re-transmitting identification data,location data and environmental state sensor data from the site serverto the common database includes transmission by internet.
 114. Anapparatus, comprising: a radio frequency tag that transmits bothidentification data and location data using hybrid spread-spectrummodulation.
 115. The apparatus of claim 114, wherein the radio frequencytag includes a power source including an energy storage device that isrecharged by at least one current source selected from the groupconsisting of a photovoltaic, a vibrational transducer, an electrostaticcharger, a radio frequency power rectifier, a thermo-electric generatorand a radioisotope decay energy recovery device.
 116. The apparatus ofclaim 114, wherein the radio frequency tag transmits environmental statedata using hybrid spread-spectrum modulation.
 117. The apparatus ofclaim 116, wherein the radio frequency tag includes a sensor.
 118. Theapparatus of claim 117, wherein the sensor characterizes at least onemember selected from the group consisting of ionizing radiation,chemical moieties, biological species, acoustic emission, mechanicalvibration and actinic radiation.
 119. The apparatus of claim 117,wherein the sensor characterizes at least one member selected from thegroup consisting of electromagnetic radiation, humidity, temperature,vibration, acceleration and mechanical interlock.
 120. The apparatus ofclaim 116, further comprising a sensor coupled to the radio frequencytag.
 121. The apparatus of claim 120, wherein the sensor characterizesat least one member selected from the group consisting of ionizingradiation, chemical moieties, biological species, acoustic emission,mechanical vibration and actinic radiation.
 122. The apparatus of claim120, wherein the sensor characterizes at least one member selected fromthe group consisting of electromagnetic radiation, humidity,temperature, vibration, acceleration and mechanical interlock.
 123. Theapparatus of claim 120, wherein the sensor includes a power source thatis not necessary for the tag to transmit identification data andlocation data.
 124. The apparatus of claim 123, wherein the power sourceincludes an energy storage device that is recharged by at least onecurrent source selected from the group consisting of a photovoltaic, avibrational transducer, an electrostatic charger, a radio frequencypower rectifier, a thermo-electric generator and a radioisotope decayenergy recovery device.
 125. The apparatus of claim 120, wherein thesensor is coupled to the radio frequency tag wirelessly by at least onemember selected from the group consisting of hybrid spread-spectrum,direct sequence spread-spectrum, frequency hopping, time hopping, timedivision multiplexing, orthogonal frequency division multiplexing andinfrared.
 126. The apparatus of claim 125, wherein identification dataand location data from the radio frequency tag is transmitted within afirst frequency band and the sensor is coupled to the radio frequencytag wirelessly within a second frequency band that does not overlap thefirst frequency band.
 127. The apparatus of claim 114, wherein the radiofrequency tag is coupled to a shipping container.
 128. The apparatus ofclaim 127, wherein the radio frequency tag transmits environmental statedata using hybrid spread-spectrum modulation
 129. The apparatus of claim128, wherein environmental state sensor data includes an environmentalstate inside the shipping container.
 130. The apparatus of claim 127,further comprising an antenna coupled to the shipping container. 131.The apparatus of claim 127, wherein the shipping container includes ashipping container power supply and the radio frequency tag can tap intothe shipping container power supply.
 132. The apparatus of claim 131,wherein the shipping container includes one member selected from thegroup consisting of a dry box and a reefer.
 133. The apparatus of claim114, further comprising a reader wirelessly coupled to the radiofrequency tag, the reader receiving identification data and locationdata from the radio frequency tag and re-transmitting identificationdata and location data from the reader to a site server that providesdata accumulation and analysis.
 134. The apparatus of claim 133, whereintransmitting identification data and location data from the radiofrequency tag occurs within a first frequency band and re-transmittingidentification data and location data from the reader to the site serveroccurs within a second frequency band that does not overlap the firstfrequency band.
 135. The apparatus of claim 134, wherein re-transmittingidentification data and location data from the reader to the site servercan include wireless transmission by at least two alternatives selectedfrom the group consisting of hybrid spread-spectrum, direct sequencespread-spectrum, frequency hopping, time hopping, time divisionmultiplexing, orthogonal frequency division multiplexing and infrared.136. The apparatus of claim 133, wherein the reader is electricallycoupled to the site server via a reader power supply line andre-transmitting identification data, location data and environmentalstate sensor data from the reader to the site server includestransmission on the reader power supply line
 137. The apparatus of claim136, wherein re-transmitting identification data and location data fromthe reader to the site server includes transmission by at least onemember selected from the group consisting of hybrid spread-spectrum,direct sequence spread-spectrum, frequency hopping, time hopping, timedivision multiplexing, orthogonal frequency division multiplexing andinfrared.
 138. The apparatus of claim 136, wherein re-transmittingidentification data and location data from the reader to the site serverincludes rejecting noise at a frequency selected from the groupconsisting of approximately 50 Hz and approximately 60 Hz andsubstantially all harmonics thereof and diversifying.
 139. The apparatusof claim 133, wherein re-transmitting identification data, location dataand environmental state sensor data from the reader to the site serverincludes wireless transmission by at least one member selected from thegroup consisting of hybrid spread-spectrum, direct sequencespread-spectrum, frequency hopping, time hopping, time divisionmultiplexing, orthogonal frequency division multiplexing and infrared.140. The apparatus of claim 140, wherein wireless transmission by hybridspread-spectrum modulation includes rejecting noise at a frequencyselected from the group consisting of approximately 50 Hz andapproximately 60 Hz and substantially all harmonics thereof anddiversifying.
 141. The apparatus of claim 133, further comprising a siteserver wirelessly coupled to the reader, the site server receivingidentification data and location data from the reader andre-transmitting identification data and location data and environmentalstate sensor data from the site server to at least one server of acommon database that provides analysis, comparison and tracking. 142.The apparatus of claim 141, wherein the common database defines a globaldatabase.
 143. The apparatus of claim 141, wherein re-transmittingidentification data and location data from the site server to the commondatabase can include transmission by at least two alternatives selectedfrom the group consisting of satellite, cellphone, acoustic, power line,telephone line, coaxial line, optical fiber and optical cable.
 144. Theapparatus of claim 141, wherein re-transmitting identification data,location data and environmental state sensor data from the site serverto the common database includes transmission by internet.
 145. Avehicle, comprising the apparatus of claim
 114. 146. A port areanetwork, comprising the apparatus of claim
 114. 147. A regional areanetwork, comprising the apparatus of claim
 114. 148. A national areanetwork, comprising the apparatus of claim
 114. 149. A global areanetwork, comprising the apparatus of claim 114.